BE570916A - - Google Patents

Description

       

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   The present invention relates to coordination circuits for remote control and indication systems) and more particularly to such coordination circuits which make it possible to share the use of a common communication channel between a coded centralized control system and a coded telemetry system.



   The use of common communication channels for several different communication and / or control systems is well known. In current practice, the well-known time-coded control system and other known centralized control systems normally share the communication channel with carrier telephone circuits, telegraph and telephone channels, and others. transmission devices. It is even possible to superimpose several remote control systems on carrier circuits, so as to increase the number of systems transmitted on the common channel.

   In the past, it has also been a common practice to use a single communication channel for centralized railway traffic control systems, especially those of the coded remote control type, and for railroad traffic control systems. usual telephone systems distributors and selectors. This use of a single communication channel has been described and represented in the case of the old technique of this scope. If each of these control systems is of the coded type, their coordination must necessarily be achieved in order to avoid harmful interaction.



   This is particularly true when the telephone selector system is of the polar code type, which is particularly well known. In this combined use, the telephone selectors are normally off the line, as their use is of a relatively low frequency compared to the operation of the centralized control system. Co-ordination circuits are therefore provided for removing the centralized traffic control system from the communication channel and for connecting the telephone selector system to this channel for the purpose of transmitting a code, but only during the period necessary for sending the messages. selector codes.

   The centralized traffic control system, which is frequently of the time-coded type, is then re-connected to the line circuit or other communication channel and can return to its original position in a normal manner. . These coordination circuits thus prevent the recording of false commands and / or false indications at the central station and at the various remote stations.



   However, various problems arise when transmitting over a common channel the codes of a remote control system, in particular when this system is of the time coded type, and of a telemetry system. Most of these problems arise from the fact that the lengths of the pulses, used in telemetry systems, have the same relative duration as the reset periods of the centralized control system. This results in a particular problem since, the telemetry codes being transmitted normally on the common channel, there is insufficient time, during these codes, to ensure the resetting of the coding apparatus in time, before the start of a new telemetry cycle.

   Thus, the time coding or remote control device, which is normally in the inoperative position and which must therefore be reset to zero to achieve synchronization before transmission of the codes, cannot enter the channel itself and deactivate the telemetry code. In other words, the main problem is to allow sufficient time for the centralized coding system to take control of the common channel and to then transmit the command or indication codes which have been stored.



   This problem is reduced to providing a device which enables the control system to be activated from its normally inactive condition, that is to say of rest, to make it seize control of the channel. The telemetry indication system should be removed from the channel and kept in a static state, until the control system comes to its initial condition and begins transmitting its code. As soon as the control system transmits a code, it is

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 capable of maintaining control of the line circuit and keeping the telemetry system inactive.

   One solution to this problem is to provide a coordination system, constituting a kind of valve which opens periodically to allow the coded remote control system to indicate its needs, with regard to the use of the line circuit, for the transmission of codes.



  If such a need does not exist, the telemetry system can continue to operate. On the contrary, if the centralized control system indicates that the use of the line circuit has become necessary for it, coordination can be effected to enable this use.



   The object of the invention is therefore to produce improved coordination circuits, which make it possible to share the use of a common communication channel between two coded control and / or indication systems.



   The invention also proposes to produce coordination circuits for a telemetry system and a coded centralized control system, so that these two systems can use the same communication channel.



   The invention also proposes to produce coordination circuits for a coded telemetry system operating normally and for a time-coded remote control system, in order to allow these two systems to share the same channel over time. Communication.



   The coordination circuit system according to the invention comprises a periodic switching device or valve, which allows a remote control system sufficient time to indicate its needs with regard to the transmission of a code, and which thus triggers the switch from a telemetry code to a control code,
In the coordination system of the invention, between two code transmission systems, one of these systems is normally active to use a common communication channel, and actuates a periodic switching device or valve, to grant the second system a period of time, during which it can indicate its needs for using the channel, and to initiate a transfer operation,

   which gives the second system exclusively control of the communication channel for the necessary period.



   Other objects and characteristics of the invention will appear in the remainder of the present application, when reference is made to the appended drawing.



   To implement the invention, a single communication channel is used, for example a two-wire line circuit, on which the codes of the telemetry system and the control and indication codes of the centralized system are transmitted successively. Normally, telemetry codes are transmitted continuously on the channel. This coding is only interrupted for the duration of the command or indication codes which are necessary. At the end of the codes from the centralized system, the telemetry codes are applied again to the channel. These codes consist of periodic cycles, each of which includes an energization period, during which current is supplied to the channel, and a period during which the channel or circuit is not energized.

   Each of these periods is of a relatively long duration compared to the durations of the signals of the other codes. The telemetry code cycle has a constant length, but its contact and break periods vary in each cycle depending on the information to be transmitted. The coordination between the two systems is carried out during the contact period of the telemetry code.



   To accomplish this coordination, a periodic switching circuit is provided at each end of the communication line. It comprises a chain of three time relays, which are energized simultaneously at the start of the telemetry code cutoff period, that is, when the communication channel is open. When the communication channel is closed, these relays drop out in a certain sequence in time, in other words, fall back in cascade. This sequence of falling relays occurs almost simultaneously

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 at the two stations, that is to say at the central station and at the field station.



  During this cascade fall of the relays, which takes place during the contact period of the telemetry code, the valve, which constitutes the chain of relays, opens to allow the introduction of a coordination pulse. In a telemetry system, whose contact period is a minimum of one second, the valve opens approximately 150 milliseconds after the line is closed, and remains open for approximately 400 milliseconds. If a centralized system control or indication code is stored, a coordination pulse is introduced on the line during this valve opening period.



  In the system shown, this pulse can consist of either a line open period or a line bypass period. The introduction of the pulse is controlled by a starting repeater relay and by the drop cycle of the periodic switching relays, the transmission of: ']! Pulse occurring approximately in the middle of the valve opening period. Receipt of the pulse at each end of the line triggers the switch to operation of the centralized control system. A disjunction relay of the telemetry system is energized at each end of the line and attracts its contacts; its operation is repeated by a trip repeater relay.



  These two relays, cooperating with the starting repeater relay, transfer the control of the coding action to the centralized control system, i.e. to the time coded system, which transmits the command and control codes. indication.



  In other words, the control of the transmission repeater relays is transferred, in each station, to the centralized control system.



   The telemetry system trip ralis, its repeater relay and the start repeater relay are kept energized, until all the necessary central control or indication codes have been transmitted.



  The sustaining energy for these three relays is supplied by a bridge relay provided in the device of the centralized control system. These three relays also have delayed drop characteristics, so as to remain energized during the time intervals between these successive codes. During this period of transmission of the command or indication codes, the telemetry readings at the central station are kept intact in the end position occupied immediately prior to the transfer operation.

   When all the necessary control or indication codes have been transmitted for any period of time, the disconnect and transfer relays lose their excitation and fall back to the rest position so as to return control of the transmission repeater relays to the relay. 'telemetry transmitter, to the field station, and to reconnect the telemetry receiver with the control system to the central station.



   If we now refer to the drawing, we see that fig. 1 schematically represents a circuit system according to the invention and arranged at a remote or field station. In the system shown, the remote measurement codes are generated at this station; the centralized control system triggers the indication codes there and receives the control codes there.



   Fig. 2 schematically represents a circuit system according to the invention, which cooperates with the circuits of the campaign station and which is located at the control station or central station of the system shown. Telemetry codes are received at the central station; centralized control codes are transmitted there and indication codes are received and stored there.



   The same reference characters denote similar parts. installation in both figures.



   To show schematically in the drawing the circuits according to the invention, conventional symbols have been used for the sake of simplicity. Some relays, such as the central station OR line relay (fig. 2), are of the polarized type and are distinguished by an arrow drawn inside the symbol of the relay coil. However, the contacts of these relays are shown in the usual horizontal position. The function-

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 nement of these relays is characterized by the fact that they do not respond to passage. current only when it passes through the relay winding in the direction of the arrow.

   In other words, the relay only works to form its "make" contacts if the excitation current flows through the winding in the direction of the arrow. When the relay is not energized or if the current crosses its winding in the direction opposite to that of the arrow, the relay remains in its rest position or passes to this position, closing its "rest" contacts. line relay F (fig. l) is of the magnetic holding type; is also represented with an arrow inside each of the symbols representing its two windingso However, we distinguish this relay from the polarized type relays by representing its contacts in the vertical position.

   According to a characteristic of magnetic holding relays, when one or the other of their windings or their two windings are excited by a current flowing in the direction of the arrows, the relay contacts switch to the normal position. , that is to say in the left position. If current flows through either winding in the opposite direction to that of the arrows, the relay contacts close in the reverse position, ie in the right position. When the relay windings lose their excitation, the contacts remain in the position to which they were last brought by the energy passing through either winding.



   Most of the other relays shown, which are of the neutral type, have delayed drop characteristics. In addition, the drop delay period of most relays is increased by the use of a half wave rectifier in parallel with the relay winding. The contacts of all delayed-drop relays are distinguished by a vertical arrow, pointing downwards and crossing the moving part of each contact, to indicate that they act with delay in that direction. When a transfer type contact of any of these relays is of the continuity type, in other words when the "make" contact closes before the opening of the corresponding "rest" contact and vice versa, a small arc is drawn. at the free end of the moving part of such a transfer contact.

   Each of the two stations shown has a local source of direct current, which may consist of a battery of accumulators of suitable size and capacity. However, for simplicity, these local batteries have not been shown; we content ourselves with representing the positive and negative limits, which we have designated respectively by the usual reference letters B and N.



   As can be seen in the drawing, the remote or centralized control system is of the single field station type. In other words, this system only includes the central station of FIG. 2 and the single field station in fig 1. These two locations are linked by a communication channel. For reasons of convenience and simplicity, this channel has been shown in the form of a two-wire line circuit which is designated in each figure by terminals L1 and L2. It is obvious, and will be understood even better as the description progresses, that it is possible to use other communication channels, such as for example simple circuits, superimposed on telephone systems, or still any of the many types of carrier channels presently available in modern technology.

   As can be seen in the drawing, the line battery LB (fig. 1), which supplies energy to the telemetry system and the centralized control system, is located at the station opposite to that where this battery is normally located. in most centralized control systems. However, during the description, it will become evident that the invention also provides for arranging the various operating elements of the coordination system, so as to be able to place the line battery at the central station. It is also of course understood that the coordination system can be modified in order to be able to use several campaign stations.

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   If we now refer to fig. 1, it can be seen that the apparatus shown in this figure and in accordance with the invention is placed at the camping station or station remote from the system. The line circuit apparatus at this station is shown across the top of the figure, with terminals L1 and L2 to the right.

   The elements of the line circuit include, a. line battery LB, current limiting resistors RLA and RLB, primary windings Pl and P2 of a pulse transformer IT, the outline of which is drawn in dotted lines, a leakage resistor RBL, and "make" and "rest" contacts of an FTPA transmission repeater relay. As can be seen in the drawing, it is evident that the energy is supplied, from the positive terminal of the battery LB, by the resistor RLA, the primary winding P1 of the transformer IT, the "on" contact. a of the FTPA relay, the terminal Ll, the terminal L2, the primary winding P2 of the pulse transformer, the resistor RLB and finally the negative terminal of the battery LB.

   When the "rest" contact a of the FTPA relay is closed, the line circuit represented by terminals L1 and L2 is bypassed and any charge stored in this circuit escapes through resistor RBL. Under these conditions, the line circuit is no longer excited, since the current of the battery LB is interrupted by the "work" contact a of the FTPA relay. The terminals L1 and L2 (fig. 1) are the same as the terminals designated in the same way in figo 2, - as will be explained a little later.



   The field station comprises a line relay FR, which is of the magnetic hold type, as indicated above. This relay perceives the control codes of the central station through the intermediary of the secondary winding S of the pulse transformer IT, as will be explained more fully a little later. drives, via its contacts a, b, which can occupy a normal position and an inverse position, the FLC line coding device of the field station, the connections being established directly on this device, except from the contact inverse to which we will describe a little later. The FLC coding device is part of the basic centralized control system.

   Since systems of this type are well known, we have been satisfied with representing the FLC device by a conventional rectangle in phantom; only certain details necessary for the understanding of the present invention have been indicated in this rectangle. For a more complete understanding of the apparatus and circuits included in such a coding device, reference is made to Instruction Manual 510, entitled "Time Coded Control System" and published in June 1955. by the "Union Switch and 'Signal Division" of the company "Westinghouse Air Brake Gompany"; reference may also be made to United States Patent No. 2,442,603 of June 1
1948.

   The systems shown in this instruction manual and in this patent can be used as centralized control systems, with the coordination circuits of the present invention.



   Inside the rectangle in phantom lines representing the coding device, conventional symbols represent the master campaign relay FM, the campaign transmitter relay FT, and the repeater relay FLBP, which forms the bridge between the pulses of the campaign code and is part of the FTC time chain also included in the coding device.

   As will be explained later, the FM relay is energized at the start of an indication code and then remains energized, thanks to a holding circuit comprising its own "make" contact a, until the indication code is finished,. The transmission relay FT is controlled by circuits internal to the coding device, so as to periodically open and close its contact a according to an alternation mode which represents the indication code to be transmitted. The repeater relay FLBP is energized during the initial group of each indication code or each command code received, during the initial operation of the time chain controlled by the line relay FR.

   As soon as the FLBP relay has been energized, it will remain energized until the code is terminated; it is one of the last relays of the coding device, which drop out at the end of any coding operation. For further details on the specific operation of the FCC counting chain,

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 of the FTC time chain and of the other internal relays of the coding device, reference will again be made to the instruction manual and the patent mentioned above.
The field station also has a chain of time relays or periodic switching FAT, FBT, and FCT.

   The FAT relay is energized by a circuit passing through terminal B, the "rest" contact b of the FTPA relay, the "rest" contact b of the FTMDC disjunction relay of the telemetry system, the "rest" contact a of the FCT relay, the winding of the FAT relay and terminal N. Closing of the "work" contact a of the FAT relay short-circuits the "rest" contact a of the FCT relay in the primitive excitation circuit and completes a hold circuit of the FAT relay, this circuit becoming effective when the "rest" contact of the FCT relay opens. The closing of the "make" contact b of the FAT relay completes an obvious circuit for energizing the FBT relay, which then attracts its contacts. The closing of the FBT relay's "make" contact completes the excitation circuit of the FCT relay and the latter also attracts its contacts.

   It is obvious that the three periodic switching relays attract their contacts more or less at the same instant, that is to say at the instant when the "rest" contact b of the FTPAo relay closes.
All of these periodic switching relays are of the delayed-drop type and each winding of these relays is provided with a half-wave rectifier in bypass to provide an additional delay when removing energization from the relays.

   The FCT relay has a short delay and a long delay on fall, thanks to the use of a resistor, which is connected at certain times in series with the half-wave rectifier. Under normal conditions, the branch circuit formed by this rectifier passes through the left terminal of the FCT relay winding, the "rest" contact a of the repeater FMSTP relay of the master relay and / or of the starting relay , the half-wave rectifier RE1 in reverse, and the right terminal of the relay winding. When the "rest" contact a of the FMSTP relay is open, the delay circuit passes through the left terminal of the winding, the resistor X, the rectifier REl in the opposite direction, and the right terminal of the winding of the relay.

   It is well known that the introduction of a resistor in series with a delay rectifier, in shunt on the winding of a relay, decreases the fall time of the latter. Thus, with the resistor X short-circuited to the "rest" contact a of the FMSTP relay, the FCT relay has a longer fall time than if this resistor is connected in series with the half-wave rectifier RE1. The operation of this delay circuit will be explained more fully when the operation of the total system according to the invention is explained.



   As already indicated, the field station apparatus comprises a repeater relay FMSTP, which repeats the operation of the starting relay FST and the master relay FM, the latter forming part of the coding device FLC. As will be seen below, one of the roles of this FMSTP relay is to transfer from the telemetry system to the centralized control system and vice versa the code transmission control circuits.

   The FMSTP relay is initially energized during the drop cycle of the periodic switching chain, that is to say when the valve that constitutes this chain is open, if the FST start relay is at rest, this relay does not drop. idle only when an indication code is stored for transmission to this field station. The FMSTP relay circuit includes the "rest" contact b of the FST relay, the "work" contact of the FBT relay, the "rest" contact "c of the FAT relay and the winding of the FMSTP relay. The contacts of the periodic switching relays are then short-circuited by the closing of the "work" contact of an FDCP repeater relay, which will be described more fully a little later.



  The FMSTP relay is kept energized for the duration of an indication code by .un. simple circuit completed by the "work" contact a of the repeater FMP relay of the master relay. During the indication codes, the FMP relay directly repeats the FM master relay, since it is kept energized by the "make" contact b of the FM relay. Initially, the FMP relay is energized by a circuit passing through the

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 terminal B, the "make" contact b of the FCT relay, the "make" contact b of the FMSTP relay, the winding of the FMP relay and terminal N.

   The FM master relay excitation circuit passes through terminal B, the "rest" contact of the FST relay, the "open" contact b of the FDCP relay, the "rest" contact c of the FCT relay, the "contact" work "c of the FMSTP relay, different circuits inside the FLC device, which are-- ,. indicated here by conventional dotted lines, but which are shown in detail in the manual and the patent cited above for reference, and finally the winding of the FM relay and the N terminal. The FM relay is kept energized by a circuit de-maintenance, completed by various contacts inside the coding device and by its own "work" contact a.

   It is thus evident that the FMSTP, FMP and FM relays cannot be energized during the periodic switching action if the storage of an indication code is not indicated by the closing of the "rest" contacts. of the FST relay.



   The chain of periodic switching relays in conjunction with the line relay FR, controls the trip relay FTMDC of the field telemetry device. If relay FR occupies its reverse position during the drop cycle of chain operation, that is to say during the valve opening period, a circuit is formed through terminal B, the contact reverse a of the FR relay, the "rest" contact d of the FAT relay, the "open" contact d of the FCT relay, the winding of the FTMDC relay and terminal N. This last relay thus excited attracts its contacts at this moment. The winding of this relay is also shunted by a half-wave rectifier, so as to increase the fall time of the relay.



  The closing of the NO contact "c of the FTMDC relay completes an excitation circuit of its repeater relay FDCP; this circuit also includes the" work "contact of the FCT relay, the" work "contact of a repeater relay TMSP telemetry holding circuit, and the winding of the FDCP relay. This relay thus excited closes its "work" contact c, so as to complete for the FTMDC relay a holding circuit also comprising the "work" contact and the winding of this last relay A circuit for maintaining the FDCP relay, completed during the coding or resetting of the FLC device, comprises the "work" contact a of the FLBP relay, this contact replacing the "work" contact g FGT relay in the initial circuit.

   The FDCP relay also has a delayed decay characteristic, which is further enhanced by its half-wave rectifier.



   When the FTMDC relay attracts its contacts, it completes or prepares, with a view to their closing, circuits by which the FR relay controls the counting chain and the time chain of the FLC coding device. Closing of the "work" contact d of the FTMDC relay closes a circuit passing through the reverse contact a of the FR relay, the "rest" contacts d of the FAT and FCT relays; this circuit is connected to one of the two connections of the counting chain relays, the other connection being made directly to the normal contact a of the FR relay. Closing of the "work" contact e of the FTMDC relay completes a circuit passing through terminal B and contact b of relay FR; this circuit is then closed alternately by the normal and reverse contacts respectively, so as to activate the chain relays in time.

   The opening of the "rest" contact b of the FTMDC relay cuts the circuit which initiates the excitation of the chain in time of the periodic switching relays, so that these relays do not operate while the centralized control system transmits its codes. . The closing of the "make" contact f of the FTMDC relay completes a circuit enabling the FR relay to respond, via its upper winding, to the secondary winding S of the pulse transformer IT ;. this operation will be described in more detail a little later.



   The field station also comprises two repeater relays FTPA and FTPB of the telemetry transmitter TT. Under normal conditions, ie when telemetry codes are being transmitted, the FTPB relay is kept energized by a single closed circuit by the "rest" contact d of the FMSTP relay. Under these conditions, the FTPA relay responds to the operation of contact a de. the telemetry transmitter, a contact that closes periodically in

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 the "working" position according to the telemetry code being transmitted.



  The FTPA relay circuit also includes at this time the "rest" contact e of the FMSTP relay. The contact a of the telemetry transmitter is shown in dotted lines in its two positions, so as to conventionally indicate that this contact operates periodically in a continuous cycle, between its upper position and its lower position. In a particular telemetry system, which can be used to transmit the telemetry codes in the system according to the present invention, the cycle of the telemetry code has a duration of 5 seconds.



  During this time interval, the "make" contact a of the transmitter can be closed for a time varying from a minimum of one second to a maximum of four seconds. Thus, the contact time of the telemetry code varies from a minimum of one second to a maximum of four seconds, while its cut-off time varies in an opposite way, from a maximum of four seconds to a maximum of four seconds. a minimum of one second. The FTPA relay transmits this telemetry code on the line circuit by periodically opening its "work" contact.!., So as to cut off the power supply between terminal Ll of the line circuit and the battery LB. The operation of the "work" contact a of the FTPA relay obviously repeats in an exact manner that of the contact a of the telemetry transmitter, as long as the "rest" contact e of the PMSTP relay remains closed.



   When the device has switched to centralized control operation and an indication code is about to be transmitted from the field station, the FTPA and FTPB relays operate in parallel. The circuit passes through terminal B, the "rest" contact a of relay FT of the FLC coding device, the "rest" contact e of the FCT relay, the "open" contact d of the FMSTP relay and the relay winding FTPB in parallel with the "on" contact e of the FMSTP relay and the winding of the PTPA relay, and finally with terminal N. The two repeater relays of the transmitter repeat, thus coding the "rest" contact a of the relay] 111 ': under these conditions.

   The "work" contact a of the FTPA relay cuts the power supplied by the battery LB in a sequence similar to that used for transmission to the central station by the line circuit. If the system has been placed in centralized control, but if no indication code is stored for transmission, so that the FMSTP relay is in the rest position, the FTPB relay remains energized by the circuit defined previously and nor- maliciously operating. The FTPA relay is also kept energized under these conditions by the circuit passing through terminal B, the "work" contact of the FTMDC relay, the "rest" contact e of the FMSTP relay, the winding of the FTPA relay and terminal N.

   The "work" contact a of the FTPA relay thus remains continuously closed, to allow the command codes to be received from the central station, in a manner which will be explained more fully a little further on.



   During the periodic switching period, if an indication code is stored for transmission, the FTPA and FTPB relays transmit the coordination pulse which performs the transfer operation. During the fall cycle of the periodic switching chain, when the FMSTP relay is energized due to the fall of the FST relay, the FTPA and FTPB relays are kept initially energized by the "work" contact c of the FBT relay, which is in parallel with the open "rest" contact of the FCT relay. During the passage of contacts d and e of the FMSTP relay from their rest position to their working position, there is no interruption in the excitation of the transmitter repeater relays, since these two transfer contacts are of the type with continuity which was defined previously.

   When the FBT relay drops out during the cycle of the periodic switching chain, the circuit of the FTPA and FTPB relays is interrupted, since the "rest" contact o of the FCT relay is not yet closed, and the two relays repeat- issuer titers fall back. These two relays are energized again when the FCT relay switches to the rest position and closes its "rest" contact; the excitation circuit of these two repeater relays starts, as already indicated, from the "rest" contact a of the FT relay, which contact is closed at this time.

   Remember; As, under these conditions, the "rest" contact of the FMSTP relay being open, the fall time of the FCT relay is shorter than under normal conditions,

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 due to the presence of resistor X in series with the RElo rectifier The fall of the FTPA relay, which opens, then its "work" contact has, produced the transmission of a coordination pulse, consisting of a line opening, in the line circuit, so as to trigger the transfer action to the central station. As will be seen below, the fall of the FTPB relay, under these conditions, allows the FR relay to switch its contacts to the reverse position for the duration of the coordination pulse.

   This action keeps the FLC device inoperative, until the contacts of this relay return to their normal positions to initiate the normal reset action before transmission of the indication code.



   As indicated previously, the relay FR responds at certain times to the current pulses induced in the secondary winding S of the pulse transformer IT. These current pulses are induced by the variations of the current flowing in the primary windings Pl and P2 of the transformer. The variation of the current can result from the breaking of the line circuit at the place of the "on" contact a of the relay FTPA, or the presence of a branch on the line circuit, at any remote location, for example at the central station, as will be explained below.

   It is obvious, since the three windings of the transformer IT are connected inductively, that the increase and decrease of the primary current causes a current to flow in opposite directions and in the form of pulses in the secondary winding. .,
However, during the operation of the "work" contact a of the FTPA relay, which contact follows the sequence of the telemetry code during transmission, it is desirable to maintain the relay FR in its normal position so as to keep it at rest. that is to say inoperative, the FLC campaign coding device.

   For this reason, a bypass is placed, during the transmission of the telemetry codes, on the secondary winding of the transformer; this derivation passes through the right terminal of the winding Se the "rest" contact f of the FTMDC relay, the "rest" contact f of the FCT relay and the left terminal of the secondary winding.-Under these conditions, the circuit , which passes through the right terminal of the upper winding of the relay FR, the "rest" contact b of the FMP relay and the "rest" contact e of the FAT relay, is open at the position of the "open" contacts f of the FTMDC and FTC relays.

   Since the circuits of the lower winding are cut in an analogous manner, the FR relay being of the magnetic holding type, maintains its contacts in the position to which they were last passed, i.e. at their normal position in the case of the centralized control system used here.



   During the telemetry code cut-off time, when the periodic switching relays FAT, FBT, FCT are all energized, the secondary winding bypass is cut at the position of the "rest" contact f of the relay FCT. However, the circuit of the upper winding of relay FR is interrupted at the same time at the position of the "rest" contact e of relay FAT. During the cascade down cycle of the periodic switching chain, the FR relay is connected to the secondary winding, so that it can respond to a coordination pulse transmitted from the central station.

   The circuit of this relay passes through the right terminal of the winding S, the "rest" contact f of the FTMDC relay, the "work" contact f of the FCT relay, the "rest" contact e of the FAT relay, the "contact" rest "b of relay FMP, the upper winding of relay FR and the left terminal of winding S. Any coordination pulse emitted by the central station causes a current to flow in this circuit in the opposite direction to that the arrow indicated in the upper winding; the relay FR therefore initially goes to its reverse position. The end of the coordination pulse returns this relay to its normal position, so as to trigger the normal reset action of the coding device.

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   However, if a code indicating the indication is to be transmitted, so that the coordination pulse is generated at the field station, the opening of the "rest" contact b of the FMP relay, opening which occurs almost immediately after the closing of the "rest" contact and of the FAT relay and before opening of the "work" contact.!. of the FTPA relay, reopens the circuit of the upper coil of the FR relay. At the same time, closing the "work" contact b of the FMP relay re-establishes the bypass on the secondary winding S. At this time, the a bypass circuit includes the "work" contact b of the FMP relay, the "rest" contact e of the FAT relay, the "work" contact f of the FCT relay and the "rest" contact f of the FTMDC relay.

   When the FTMDC relay attracts its contacts, its "fravail" contact short circuits the f contact of the FCT relay in the branch circuit and the branch is held on the secondary winding during transmission of the indication code.



   If an indication code must be transmitted, the relay FR is also initially maintained in its normal position by the circuit passing through terminal B, the "work" contact c of the FMP relay, the "work" contact a of the FTPB relay, the lower winding of the FR relay, the "open" contact ¯b of the FTPB relay and finally the N terminal; current flows in the direction of the arrow in the lower winding. When the FTPB relay drops to rest during the transmission of a coordination pulse, as previously explained, its contacts a and b change the circuit polarity of the lower coil of the FR relay, so that the current passes in the opposite direction through the lower winding and allows the FR relay to change to the reverse position.

   At the end of the pulse, the FTPB relay attracts its contacts and again changes the polarity of the circuit of the lower winding of the FR relay, so as to bring this relay back to its initial position; relay FR therefore goes to its normal position to trigger the normal reset action of the FLC coding device. During the transmission of an indication code, the operation of the FTBP relay, which repeats the operation of the "rest" contact a of the FT relay, drives the FR relay alternately to its reverse position and to its normal position. , so as to follow the code.

   The operation of contacts a and b of relay FR drives, under these conditions, the coding device so as to advance the code in the usual way, as explained in the instruction manual and in the patent, both cited above by reference. During the reception of a command code emitted by the central station, the relay FR is controlled by the pulses induced in the winding S of the pulse transformer; the control circuit of this relay passes through the winding S, the "work" contact f of the FTMDC relay, the "rest" contacts e and b belonging respectively to the FAT and FMP relays, and finally the upper winding of the relay FR.



   Another relay control circuit FR passes through terminal B, the "rest" contact d of the FBT relay, the "open" contact f of the FAT relay, the "open" contact a of the FTPB relay, the internal winding of the relay FR, the "make" contact b of the FTPB relay and finally the N terminal. This circuit is completed almost instantaneously when the relays of the periodic switching chain are successively energized. It ensures that the FR relay is maintained in its normal position at the start of the telemetry code cutoff period, to counteract any effect produced on its upper winding by the secondary winding S of the pulse transformer.



   If we now refer to fig. 2, it can be seen that the apparatus shown in this figure comprises, as indicated above, the central station operating with the field apparatus of FIG. 1, in the case of the system according to the invention. In the upper left part of fig. 2, we see the connections of the line circuit. The terminals Ll and L2 are equivalent to the bor. analogous shown in fig, 1 and represent the connections of the communication channel to the central station; this channel has been chosen, for simplicity, as being a two-wire line circuit, in the present application.

   The line circuit connections pass through the positive line L1, the "work" contact,

  <Desc / Clms Page number 11>

 of the repeater OTP relay of the central station transmitter, the winding of the OR line relay of the central station and the L2 line. The OR line relay, which is of the polarized type, follows telemetry codes and centralized indication codes, which are transmitted by the field station. The operation of the OR relay is repeated by the ORP repeater relay, which is a repeater with "rest" contact, comprising a simple excitation circuit passing through the "rest" contact a of the OR relay and the winding of the ORP relay. This last relay follows the code received by the OR relay in the opposite direction, energizing each time the OR relay drops to rest.

   The line circuit is shunted at certain times by the fall of the OTP relay closing its "rest" contact a. This shunt short-circuits the winding of the OR relay, which drops out; produces an increase in line current, eliminating the resistance of the OR relay winding. As will be seen a little later, the operation of the OTP relay repeats the sequence of the command code being transmitted, which is then received at the field station. The system therefore differs from two shown in the instruction manual and in the patent already cited by reference.

   It differs in particular from that of the patent, in which the control codes are transmitted by opening the designated circuit to the central station and the indication codes are transmitted by bypassing the line circuit to the field stations. In the present case, on the contrary, where the line battery is located at the field station, it is necessary to reverse the usual mode of operation. However, it is understood that this operating system can be modified, within the scope of the invention, so as to use the method represented in the two documents cited by reference.



   Like the field station, the central station comprises a chain of time relays or periodically switched OAT, OBT and OCT. These relays function like the time relays of the field station, which have been described above. The OAT relay excitation circuit passes through terminal B, the "work" contact a of the ORP relay, which closes each time the line relay drops, to indicate a telemetry code cutoff period, the "rest" contact b of the central station telemetry disjunction OTMDC relay, the "rest" contact a of the OCT relay, the winding of the OAT relay, and terminal N.

   The "work" contact a of the OAT relay closes, when this relay is energized, so as to short-circuit the "rest" contact a of the OCT relay, and make a holding circuit for the first relay in time. The closing of the "work" contact b of the OAT relay completes an excitation circuit of the second relay at OBT time. The closing of the "work" contact of this second relay completes an excitation circuit of the third relay at OCT time. The three time relays in the chain are thus energized at approximately the same instant, at the start of each break period of the telemetry coding cycle.

   The drop cycle of the chain of relays, cycle which corresponds to the opening period, of the valve constituted by this chain, takes place during the contact period of the telemetry code, exactly as at the field station. It is obvious that the relays fall back in cascade in the order in which they are successively excited.



   Each relay in the time chain has fall-delay characteristics, which are further amplified by the half-wave rectifier connected in parallel with each relay winding. The OCT relay has two delayed fall periods, one of which is shorter than the other. Normally, this OCT relay has a slightly longer delayed decay period than the other two periodic switching relays; its delay circuit passes through the left terminal of its winding, the "rest" contact a of the QMSTP relay, repeater of the master-relay and / or of the start-up relay, the half-wave rectifier RE2 in the opposite direction, the terminal N and the right terminal of the winding.

   If the "rest" contact a of the OMSTP relay is open, the delay circuit comprises a resistor Y and the rectifier RE2, and the drop-off time of the relay, as explained previously, is shorter when this resistance is connected in series with the rectifier in the delay circuit.

  <Desc / Clms Page number 12>

 



   The OMSTP repeater relay of the master relay and / or the start relay at the central station is energized during the chain drop cycle in time when the OST start relay is at rest. As can be seen in the drawing, the OST relay only loses its excitation in the event that a control code is stored for transmission. The OMSTP relay is thus energized, so as to transfer or complete the code transmission control circuits and to allow the central station to transmit a control code. The OMSTP relay excitation circuit passes through terminal B, the "rest" contact b of the OST relay, the "rest" contact c of the OAT relay, the "work" contact b of the OBT relay, the winding of the OMSTP relay and terminal N.

   This circuit is obviously completed during the period of falling off the chain in time, that is to say during the period when the valve is open. The "work" contact a of the ODCP cut-off repeater relay, at the central station, short-circuits contacts c and b of the respective OAT and OBT relays, so as to keep the OMSTP relay energized until the moment when the final holding circuit of this relay can be completed. This maintenance circuit includes the "work" contact b of the master relay OM of the central station. This OM relay is located inside the central station OLC line coding device, a device conventionally represented by a rectangle in phantom (fig. 2).

   This coding device is analogous to the FLC campaign coding device shown in FIG. 1; it has been described in detail in the instruction manual and in the patent already cited by reference. Only the parts of the coding device which are necessary to understand the invention have been shown here; to know the complete arrangement of the internal circuits of the coding device, one will again refer to the two documents mentioned above.



   The OM relay is energized when a centralized control code is to be transmitted, after the transfer has been made from the telemetry system to the centralized control system. Its excitation circuit passes through terminal B, the "rest" contact a of the OST relay, the "rest" contact b of the OCT relay, the "work" contact b of the ODCP relay, the "work" contact b of the relay OMSTP, circuits internal to the coding device and conventionally represented by a dotted line, the winding of the OM relay and the N terminal. The OM relay is now then energized, until the end of the transmission of the control code, by a holding circuit comprising its own "work" contact and completed by various relay contacts and various internal circuits in the OLC coding device.



   The OTMDC telemetry disjunction relay of the central station is similar, in operation, to the trip relay of the field station. The OTMDC relay is energized when the OR line relay receives a current in the opposite direction and when the valve constituted by the time chain is opened. Its excitation circuit passes through terminal B, the "rest" contact a of the OR relay, the "rest" contact d of the OAT relay, the "work" contact c of the OCT relay, the winding of the OTMDC relay and the terminal NOT.

   The ODCP di-junction repeater relay is energized by the closing of the "work" contact c of the OTMDC relay, its excitation circuit also includes the "work" contact d of the OCT relay, the "work" contact a of an OTMSP relay telemetry hold repeater, the "rest" contact has push-button PBP repeater relay and the ODCP relay coil. Closing of the "work" contact c of the ODCP relay completes the holding circuit of the OTMDC relay; this circuit also includes the "work" contact and the winding of the latter relay.

   The ODCP relay is kept energized, throughout the duration of any centralized code, by the circuit completed at the location of the "work" contact a of the OLBP repeater bridge relay forming a bridge, which is part of the time chain of the OLC coding device; this circuit is completed on the other hand by the "rest" contact d of the OCT relay, and closes by rolling up the ODCP relay, following the path already indicated. The OLBP relay is energized during the first group of any centralized code and remains energized for the duration of the code; it drops out during the final code group when the central control system returns to its normal condition.

  <Desc / Clms Page number 13>

 



   The OTMDC relay works to complement the circuits by which the OR line relay drives the OLC coding device of the central station, to advance the operation of the count chain and the chain in time during command codes. and indication codes.

   The closing of the "open" contact d of the OTMDC relay closes the circuit from terminal B of
 EMI13.1
 the local source up to contacts ¯b and .2. of the OR relay, the "on" and "off" contacts. 2. completing the connection of] -laahaîne in time on its two control wires, while the "work" contact b completes the circuit leading to one of the two wires controlling the counting chain of the:. coding device.
 EMI13.2
 The circuit extending from contact ¯a of the OR relay to the other control wire of the counting chain is completed by closing the "work" contact e of the OTMDC relay; this circuit also comprises the "rest" contact c of the OCT relay and the "rest" contact d of the OAT relay.



   The OTMDC relay operates on the other hand in such a way as to interrupt the operation of the TRM telemetry receiver. The opening of its "rest" contact f cuts the current supplying the control contact of the receiver while the opening of the "rest" contact stops the operation of the motor of the receiver.



  The interruption of these two circuits of the telemetry receiver keeps intact
 EMI13.3
 the existing indicator of the receiver, the last information received being thus maintained until the telemetry codes are returned to the line. The control contact circuit of the TMR telemetry receiver also includes the "rest" contact b of the ORP relay, which contact follows the sequence of the code received by the line relay OR. However, the power supply being interrupted at
 EMI13.4
 the place of the "rest" contact f of the OTüDG relay, the control contact of the TMR receiver does not work during the transmission of codes from the centralized control system.

   The final function of the OTMDC relay is to interrupt the operation of the chain of periodic switching relays, the opening of its "rest" contact b cutting the OAT relay excitation circuit. This chain obviously does not work, while the centralized control system is connected to the line circuit.



   The TMR telemetry receiver has conventionally been represented by a rectangle in phantom, since the details of this receiver are well known. On the other hand, these details do not intervene in the operation of the coordination circuits according to the invention and it suffices to describe the control of the energy supplied to the TMR receiver.



   The central station has an OTP transmission repeater relay, which is kept energized normally, that is to say, during the transmission of the telemetry codes from the field station, by means of a simple circuit
 EMI13.5
 comprising the contact t "'rest" 0 of the OMSTP relay and the winding of the OTP relay.' When the centralized control system is operating, the OTP relay is controlled by the OT transmitter relay contained in the central station OLC line coding device.

   Under these conditions, its control circuit passes through terminal B, the "rest" contact a of the OT relay, the "rest" contact e of the OCT relay, the "work" contact o of the OMSTP relay, the winding of the OTP relay , and terminal N.
 EMI13.6
 The transmitter-OT relay is controlled, as has been explained in detail in the instruction manual and the patent already cited, by the counting chain OCC so as to form the control codes transmitted by the coding device.



  Its "rest" contact thus repeats the sequence of the desired control code and this sequence is repeated again by the operation of the OTP relay. The func-
 EMI13.7
 operation of the OTP relay, repeating the code, activates its contact ¯a between a rest position and a working position; thus, this relay bypasses and alternately restores the line circuit extending from the battery of the field station. The alternating increases and decreases in line current serve to transmit the desired control code; the OR relay also follows this code, because its excitation circuit is cut each time the "work" contact a of the OTP relay opens.

  <Desc / Clms Page number 14>

 



   During the cascading period of the periodic switching relays, if a control code is stored for transmission from the central station, the OTP relay is actuated to transmit a coordination pulse into the line circuit. Under these conditions, the OTP relay is kept energized during the operation of the periodic switching chain by means of the "work" contact c of the OBT relay, until this relay drops to rest. At this moment, the OCT relay is energized, so that its "rest" contact e opens. The OTP relay circuit, a circuit passing through the "on" contact d of the OMSTP relay and through the "rest" contact a of the OT relay, is thus cut off during the fall period of the OCP relay and the OTP relay loses consequently his excitement.

   The coordination pulse is therefore produced by a line shunt completed by the "rest" contact a of the OTP relay. When the OCT relay drops out at the end of its short delay drop period, following * opening of the "rest" contact of the OMSTP relay, the OTP relay is energized by the circuit defined above and the coordination pulse. end. It should be noted that, when the OMSTP relay is energized in these conditions following the fall of the OAT relay, so as to close its "rest" contact c, the OTP relay is kept energized during this period, because the contact transfer rate c of the OMSTP relay is type 4 continuity; the winding of the OTP relay therefore never loses its excitation during the transfer operation.

   Thus a single coordination pulse is transmitted at the appropriate time.



   The OTHSP and PBP relays, also represented at the central station and mentioned briefly above, perform certain synchronization and coordination actions under special conditions. We will understand the operation of these relays when we explain the operation of the whole system a little further on, -
The system is shown in the drawing in its telemetry position. The relays are shown in the positions they occupy just before the end of a contact pulse of a telemetry indication. At the field station (fig. 1) contact a of the telemetry transmitter is closed; it should be remembered that the two positions of this contact are represented by a dotted line because it opens and closes continuously.

   With contact a of the telemetry transmitter closed, the FTPA relay is energized and its "working" contacts are closed as seen in the drawing. The line circuit L1, L2 is thus excited by the line battery LB and through the "work" contact a of the FTPA relay, so that the OR relay of the central station (figo 2) is energized and attracts its contacts. . It will be remembered that the periodic switching operation takes place during the contact period of the telemetry ... However, as can be seen in the drawing, this switching operation is completed, so that the relays of the switching chain periodically are in rest o In other words, the FAT, FBT, and FTC relays now occupy their rest positions with their "make" contacts open.

   The field station FST start relay is energized at this time, since no indication code is stored, and its "rest" contacts a and b are open. The FR relay occupies its normal position at this time, with all its control circuits cut off. When the FCT relay is released, the opening of its "work" contact f has cut the circuit of the upper coil of the FR relay. The circuit of the lower winding of relay FR is also cut at the location of the "on" contact c of the FMP relay and at the location of the "on" contact f of the FAT relay. The secondary winding S of the pulse transformer IT is shunted at this time by a circuit, comprising the "rest" contacts f of the FCT and FTMDC relays.

   All other relays in the station are in the off position, including the relays shown inside the FLC coding device.



   At the central station, the ORP relays being at rest since the "rest" contacts of the OR relay are open, the periodic switching relays OAT, OBT and OCT, are also at rest. Since the OST relay is energized, no control mode was stored, the OMSTP relay was not energized during the period.

  <Desc / Clms Page number 15>

 switching switch which has just ended and is now in the rest position o As a result, the OTP relay is energized by the "rest" contact c of the OMSTP relay. The line circuit extending from the terminals L1, L2 to the line relay OR is completed by the "working" contact a of the OTP relay and this circuit remains in this condition as long as the telemetry operation continues.

   The other relays shown at the central station are also all not energized and therefore in the rest position. As a result, energy is transmitted to the TMR telemetry receiver, so that the motor runs and the control contact responds to the operation of contact b of the ORP relay.



   It is assumed that the transmission of telemetry continues; contact a of the telemetry transmitter at the field station opens and causes the fall of the FTPA relay. This results in the opening of the connection of the line battery at the location of the "working" contact a of this relay and the removal of the supply to the line circuit; the OR relay of the central station therefore falls back to idle. The station's FR line relay is kept in its normal position, since its control circuits are cut at this time and the secondary winding of the IT transformer is bypassed. At the station, closing the "rest" contact b of the FTPA relay energizes the FAT relay, which attracts its contacts. This action is immediately followed by the energization of the FBT and FCT relays, which also attract their contacts.

   The relays of the periodic switching chain remain in the working position as long as the "repds" contact b of the FTPA relay remains closed.



   At the central station, the removal of the excitation and the drop of the OR relay, which closes its "rest" contact a, produce the excitation of the ORP relay, which attracts its contacts. Closing of the "work" contact a of the ORP relay energizes the OAT relay and this energization is immediately followed by that of the OBT and OCT relays. Thus, it can be seen that the periodic switching relays, at the field station and at the central station, pass successively into the excitation position, immediately after the start of the period for switching off the telemetry code.

   Continuous operation of the contact from the telemetry transmitter to the field station, continues the transmission of the telemetry code, which is transmitted over the line circuit by the FTPA relay, then received at the central station by the OR relay, and which controls the TMR telemetry receiver via the operation of contact b of the ORP relay. The encoding cycle of the remote measurement transmitter is repeated indefinitely and its duration is equal to 5 seconds, as already indicated, in a particular well known system.



   It will now be assumed that the operator of the system wishes to send a control code from the central station to the field station, which control code is transmitted by means of the centralized control system shown here. The operator positions a control device and causes the OST start relay to drop so as to store the control code.



  When contact a of the telemetry transmitter closes again at the station, energizing the FTPA relay, which closes the line circuit so as to energize the OR relay, the ORP relay of the central station loses its excitation and falls immediately. - diatement at rest. Switching the FTPA relay to the work position and the drop of the ORP relay to the rest position simultaneously initiate the periodic switching operation at the central station and at the field station. At the central station, the excitation of the OAT relay is removed by opening the "work" contact of the ORP relay and this OAT relay drops to rest, at the end of its fall delay period, so as to open its contacts. "job". The actual periodic switching period begins at this time.

   The OST relay being released, and its "rest" contact b being consequently closed, the closing of the "rest" contact c of the OAT relay completes the excitation circuit of the OMSTP relay, this circuit also including the "work" contact. b of the OBT relay. Thus excited, the OMSTP relay attracts its contacts and its transfer contact c transfers the control of the OTP relay to the circuit comprising the contact a of the OT relay of the OLC coding device.

  <Desc / Clms Page number 16>

 



   At this time, the "make" contact C of the OBT relay is closed, so that power is continuously supplied to the OTP relay during this transfer action and for a subsequent period; this relay remains energized and keeps the line circuit closed by its "work" contact a. It should be noted that at this moment the opening of the "rest" contact a of the OMSTP relay modifies the delay circuit connected in parallel with the winding of the OCT relay, so as to change this relay from its long drop period to its short fall period.

   Since the OBT relay has lost its excitation following the opening of the "work" contact b of the OAT relay, it falls back to rest at the end of its delayed drop period by removing the excitation of the OCT and OTP relays; the removal of the excitation of this last relay results from the opening of the "work" contact c of the OBT relay, since the "rest" contact e of the OCT relay remains open.



   Its winding was not energized, the OTP relay drops out immediately by opening its "work" contact a and closing the corresponding "idle" contact, so as to bypass the line circuit while removing the excitation of the OR relay , which falls immediately o The bypass of the line circuit transmits the coordination pulse passing through the line circuit to the field station; the action of this impulse at the campaign station will be explained a little later.

   At the central station, the fall of the complete OR relay by its "rest" contact has the OTMDC relay excitation circuit; this circuit is thus completed at this intermediate stage of the operation of the time chain or of periodic switching, when the "rest" contact d of the OAT relay and the "work" contact c of the OCT relay are closed. Closing of the "work" contact c of the OTMDC relay completes a circuit passing through the "work" contact d of the OCT relay to energize the ODCP disjunction repeater relay, which then attracts its contacts. The closing of the "open" contact d of the OTMDG relay supplies energy, through the "rest" contact c of the OR relay, to a connection of the chain in time.
OTC of the OLG device.

   The OTC time chain and therefore the device
OLC thus pass to the reverse position under the influence of the fall of the relay
OR and the OTMDC relay excitation. The OLBD relay is energized and attracts its contacts during this chain operation, in particular by closing its "work" contact a. The circuits leading to the OCC counting chain of the OLC device are open at this moment and no action therefore takes place in these circuits.

   With the "rest" contact b of the OCT relay open, the OM relay excitation circuit is cut o Later, when the "rest" contact b of the OCT relay closes, the circuits inside the OLC coding device are shown in dotted lines. on the drawing will be open to prevent the OM relay from being energized at this time o
The OCT relay drops out, after the OBT relay drops, at the end of its short delayed drop period.

   Closing its short "rest" contact.; - circulates the open "work" contact of the OBT line, again energizing the OTP relay, which closes its "work" contact to re-establish the line circuit, by terminating to the coordination pulse emitted by the central station It should be noted that, with the OM relay at rest, the OT relay of the coding device remains not energized, so that its "rest" contact is closed to complete the relay circuit OTP. By terminating the coordination pulse, at the end of the short delay period for the fall of the OCT relay, one is sure that this action occurs before the fall of the FCT relay, which ends the period. switching to the field station and allows variations in the fall time of the latter relay.



   The OTMDC relay remains energized thanks to its holding circuit comprising the "open" contact c of the ODCPo relay. The "open" contact of the OLBP relay, placed in the coding device, is closed during this period long enough so that, in combination with the delay period when the ODCP relay drops out, the latter relay maintains its "make" contacts closed during this time: - valle, The OMSTP relay remains energized at this moment by the "work" contact has a delay ODCP, which short-circuits the "work" contact b, now open, of the relay:

  <Desc / Clms Page number 17>

 OBT.

   The OR relay is energized again, when the line circuit is reestablished and it attracts its contacts, passing the OLC coding device to its normal position by means of the OTC time chain activated by the contact " work "c of the OR relay; the coding device then returns from its normal position to its idle condition. This resetting action has been fully described in the publications mentioned above, to which reference may be made to better understand this operation.



   At the field station, the bypass applied to the line circuit at the central station causes relay FR to switch to its reverse position, in response to the pulse induced in the secondary winding S of the pulse transformer IT. At this moment, during the operation of the periodic switching chain, the FAT relay has dropped out at about the same time as the OAT relay of the central station and the FCT relay is still in the working position. Thus, the circuit, comprising the secondary winding S and the upper winding of the relay FR, is completed by the "rest" contact b of the FMP relay, the "rest" contact e of the FAT relay, the "work" contact f of the FCT relay and the "rest" contact 1. of the FTMDC relay.

   Switching relay FR to its reverse position, while closing its reverse contact a, completes the excitation circuit of the FTMDC relay; this circuit also includes the "rest" contact d of the FAT relay and the "open" contact d of the FCT relay. The FTMDC relay thus excited attracts its contacts and completes the excitation circuit of the FDCP relay with its "work" contact; this circuit also includes the "work" contact g of the FCT relay and the "work" contact a du., - TMSP relay. Closing the contact f of the FTMDC relay short-circuits the f contact of the FCT relay in the circuit connecting the upper winding of the relay FR to the secondary winding S of the pulse transformer IT.

   As the FR relay is already in its reverse position, closing the "on" contact e of the FTMDC relay energizes the relays of the FTC time chain of the FLC coding device, by passing this chain of relays and this device to their position. reverse.



  This timely operation of the chain causes the closing of contact a of the FLBP relay and thus maintains the FDCP relay energized by means of a second circuit The contact. ±. With the FDCP relay closed, the FTMDC relay holding circuit can keep the latter relay energized when the possible drop of the FCT relay occurs.

   It should be noted that the circuit of the FCC counting chain of the FLC coding device is interrupted-under these conditions at the location of the "rest" contact d of the FCTo relay. The FTPA relay is energized at this moment by the intermediary of the contact. "work" g of the FTMDC relay and of the "rest" contact e of the FMSTPo relay The "work" contact a of the FTPA relay being kept closed, the power supply of the line circuit from the LB battery is ensured in the conditions described.



   When the central station OCT relay drops, at rest, energizing the OTP relay so as to remove the bypass established on the line circuit, the FR relay returns to its normal position under the action of the current of opposite direction induced in the secondary winding S of the pulse transformer IT; the circuit of this pulse then comprises, as has already been explained, the "work" contact f of the FTMDC relay. This operation of the FR relay returns the FLC coding device to its normal position and the relays in the time chain drop to rest, bringing the coding device back to its rest condition, as explained in the publications cited above. high in reference.

   The delay period of the FDCP relay is sufficient to render inoperative the possible interruptions of the power supply made by the "work" contact a of the FLBP relay during this reset action. This passage of the FR relay to its normal position occurs at the same time as the OR relay of the central station returns to its normal position, so that the coding devices of the central station and the field station are reset at the same time. time from their normal position. The fall of the FCT relay of the field station occurs after this operation of the line relay, since the fall period of this FCT relay is maintained at its long value by the closed "rest" contact of the relay. FMSTP.

  <Desc / Clms Page number 18>

 



   The control code, stored at the central station, can now be transmitted as soon as the coding devices have returned to their idle condition. The OM relay is energized as soon as this condition is obtained; the rest of the circuit is completed by the "rest" contact a of the OST relay, the "rest" contact b of the OCT relay, the "work" contact b of the ODCP relay, and the "work" contact b of the OMSTP relay. The OM relay remains energized by its holding circuit represented in a conventional manner; it also keeps the OMSTP relay energized by the completed circuit at the location of the "work" contact b of the OM relay.

   With the OCT relay at rest, the circuits passing through the contacts of the OR relay are closed on the counting chain and on the time chain, so as to allow complete operation of the OLG coding device. The OT relay is driven by this operation, as was explained in the printed publications cited above by reference, and the operation of its "rest" contact actuates the OTP relay, so as to alternately bypass and re-establish the line circuit, by actuating the line relays OR and FR between their two positions o During the transmission of these centralized codes, the relays of the central station periodic switching chain cannot operate, because the contact " working "b of the OTMDC relay is open and cuts the OAT relay excitation circuit,

   by thus preventing the excitation of this relay and at the same time that of the two other relays of this chain. At the field station, a similar result is obtained by the FTMDC relay, at the location of its "rest" contact b, which is also open at this time. The DCP relays of the central station and of the field station are kept energized during the coding action by means of the "work" contact of each corresponding repeater relay LBP; these DCP relays therefore keep the TMDC relay holding circuits closed at the corresponding "work" contacts c. At the central station, the "rest" contacts f and g of the OTMDC relay cut off the power supply to the control contact and to the motor of the TMR telemetry receiver respectively.

   The motor was not energized and the control contact being ineffective, the telemetry indicators are held in position, so as to maintain the existing reading during the interruption of the telemetry coding.



   If an indication code is to be transmitted from the field station, after the end of the command code, as indicated by the drop of the FST relay, the FMSTP relay circuit is completed by the "rest" contact b of the FST relay and by the "work" contact a of the FDCP relay, the latter contact remaining closed. The circuit of the FM relay of the coding device is completed by the "rest" contact of the FST relay, the "working" contact b of the FDCP relay and the "working" contact c of the FMSTP relay, so that the coding device can be switched on. excited and pass the code.

   All these centralized codes, which are necessary at this moment, are transmitted successively; the system, comprising the circuits according to the invention, keeps the telemetry system inactive and the centralized system connected to the line circuit for as long as necessary.



   At the end of all these centralized codes, the system returns to the transmission of telemetry codes o At the central station, the OM relay drops to rest, removing the excitation of the OMSTP relay, the initial circuit of the latter relay being opened by the "rest" contact b of the OST relay, which attracts its contacts during the transmission of the final command code emitted by the central station. The OMSTP relay being at rest, the closing of its "rest" contact c completes a circuit supplying energy to the OTP relay; the latter thus keeps the "working" contact a closed, so that the line circuit, passing through the coil of the OR relay, remains closed.

   The fall of the OLBP relay, during the final element of any centralized code, suppresses the energization of the ODCP relay; this one drops if necessary, by opening its "work" contact c, so as to suppress :) the excitation of the OTMDC relay, the fall of which occurs after a moment o The fall of this relay returns the control of the chain of periodical switching relays to the "on" contact a of the ORP relay and cuts off the circuits by which the OR relay controls the timing chain and the counting chain of the OLG coding device. The central station therefore returns to its condition allowing it to receive:

  <Desc / Clms Page number 19>

 telemetry codes on the line circuit.



   At the field station, the fall of the FLBP relay suppresses the excitation of the FDCP relay, which drops out and in turn suppresses the excitation of the relay.
FTMDC The fall of this returns the command of the FTPA relay to contact a of the telemetry transmitter TT, so as to allow the subsequent transmission of the telemetry codes. Closing the "rest" contact f of the FTMDC relay re-establishes the shunt on the secondary winding S of the pulse transformer.
IT, by removing the control of relay FR at this time.

   Closing the "rest" contact b of the FTMDÔ relay restores control of the chain of periodic switching relays on the "rest" contact b of the FTPA relay. At this time, the field station device is reduced to the condition, in which the telemetry codes can be transmitted by the telemetry transmitter TT, through the operation of its contact a.



   It will now be assumed that an indication code must be transmitted from the field station 0 In other words, the operation of an indication device causes the drop of the FST start relay. During the next contact period of the telemetry code, the FTPA relay, energized by contact a of the telemetry transmitter, attracts its contacts by closing the line circuit so as to re-energize the OR relay of the central station The relay line FR of the field station remains in its normal position shown in the drawing.

   The opening of the "rest" contact b of the FTPA relay suppresses the energization of the periodic switching relay FATo. When this relay drops to rest, at the end of its fall delay period, so as to open the control valve. coordination, the excitation circuit of the FMSTP relay, has been completed This circuit passes through terminal B, the "rest" contact b of the FST relay, the "open" contact b of the FBT relay, the "rest" contact c of the FAT relay, the winding of the FMSTP relay and the terminal No Pulling the contacts d and e of the FMSTP relay transfers the control of the FTPA and FTPB relays to the contact of the FT relay of the FLC coding device.



   At this moment, the "work" contact c of the FBT relay being closed, the two repeater relays of the transmitter do not lose their excitation during this transfer operation and the transfer contacts of the continuity type guarantee a continuous supply of the windings of the transmitters. relayo These relays remain energized, the line circuit remains closed and the FR relay remains in its normal position.
It should be noted that the opening of the "rest" contact a of the FMSTP relay changes the fall time of the FCT relay from its normal long period to its chosen short period, resistor X being interposed in series with rectifier RE1 in forming a circuit connected in parallel with the relay winding.



   The "work" contact b of the FCT relay being closed, closing the "work" contact b of the FMSTP relay energizes the FMP relay, which attracts its contacts. The circuit passing through the "work" contact a of the FMP relay keeps the FMSTP relay energized; although the initial circuit of this one is still closed However, the closing of the "work" contact b of the FMP relay re-establishes on the secondary winding
SU of the pulse transformer IT the bypass, which had been interrupted by the opening of the "rest" contact f of the FCT relay.

   The new branch circuit passes through the left terminal of the secondary winding, the "open" contact b of the FMP relay, the "rest" contact e of the FAT relay, the "open" contact f of the FCT relay, the "contact" rest "f of relay FTMDC 'and finally the right terminal of the secondary winding So
The fall of the FBT relay, at the end of its delayed fall period, following the fall of the FAT relay, suppresses the excitation of the FTPA relays and
FTPB, which fall immediately.

   The opening of the "work" contact has relay
FTPA cuts the line circuit so as to transmit a coordination pulse to the central station This line opening pulse removes the excitation of the OR relay and causes it to fall back o A similar coordination pulse is registered at the station campaign by passing the relay FR to its reverse position; the current is supplied for this purpose by the circuit passing through terminal B, the "working" contact c of the FMP relay, the "rest" contact b of the FTPB relay, the winding

  <Desc / Clms Page number 20>

 of the FR relay in the opposite direction to the arrow, the "rest" contact a of the FTPB relay and the N terminal.

   The flow of current in this circuit allows the relay FR to close its contacts inverseso The closing of the reverse contact a of the relay FR completes the previously traced circuit of excitation of the FTMDC relay, this circuit also passing through the "work" contact d of the relay FCT. The "work" contact c of the FTMDC relay being now closed, the excitation circuit of the FDCP relay is completed and this relay attracts its contacts. The previously defined holding circuit of the FTMDC relay is now complete and the FDCP relay closes its "working" contact a to also keep the FMSTP relay energized, if the FMP relay drops quickly.

   Closing of the "on" contact e of the FTMDO relay completes the circuit passing through the reverse contact b of the FR relay and serving to trigger the reverse operation of the time chain of the coding device. FLC. The branch circuit of the secondary winding S is transferred at this time to the "on" contact f of the FTMDC relay, which bypasses the "on" contact f of the FCT relay.



   The FCT relay, the excitation of which is removed by opening the "work" contact a of the FBT relay, drops out at the end of its short drop period, which is active at this time. Closing of the "rest" contact e of the FOT relay re-establishes the circuit to energize the FTPA and FTPB relays again, the "rest" contact of the FT relay remaining closed during this period o Closing of the "work" contact of the relay FTPA ends the coordination pulse transmitted to the central station;

   the reversal of the current flowing through the lower winding of the FR relay, reversal due to the action of changing the polarity of the contacts a and b of the FTPB relay, returns the FR relay to its normal position., The short period of delayed fall of the FCT relay is thus terminated at the coordination pulse, before the closing of the periodical switching period at the central station, which is controlled by the longer duration of the fall of the OCT relay. Note that the FM relay excitation circuit is cut at the position of the 'rest' contact c of the FCT relay before the latter falls.

   At this moment, the circuit external to the coding device FR and serving for the GM relay is completed, but the excitation circuit of this relay remains however interrupted by the action of the time chain inside the coding device, so that the FM relay remains non-energized. The opening of the FCT relay "make" contact b removes the excitation of the FMP relay, but the "make" contacts of the latter remain closed during its delayed fall period. Switching the FR relay to its normal position again energizes the relays in the chain in time and triggers a normal reset action of the FLC coding device.

   This long-term operation of the chain keeps the "make" contact a of the FLBP relay closed for a period sufficient to supply the FDCP relay with current so that the latter, regardless of its delayed drop characteristic, maintains its contacts. "work" closed during this reset action.



   At the end of the on-time chain reset action, the FLC encoder is ready to transmit an indication code. The FM relay circuit is closed and this relay therefore attracts its contacts, again energizing the FMP relay which then keeps the FMSTP relay energized during the entire indication code. The initial circuit of the FMSTP relay, passing through the "rest" contact b of the FST relay, is interrupted when the latter relay draws its contacts, during the progress of the coding action.

   The "make" contacts d and e of the FTMDC relay are closed, so that power can be supplied to the time chain and to the count chain of the FLC coding device in the usual way by the contacts. a and b respectively normal and inverse of relay FR. During the coding action, the alternate opening and closing of the "rest" contact a of the FT relay controls the FTPA and FTPB relays so as to make them follow the code.

   The alternate opening and closing of the "work" contact a of the FTPA relay transmits the code via the line circuit to the central station The alternating operation of the contacts a and b of the FTPB relay, between their rest and work positions, actuates relay FR, between its reverse position and its nominal position, so as to control the coding of the circuits inside the FLC device.

  <Desc / Clms Page number 21>

 



  During this coding action, the "make" contact a of the FLPB relay remains continuously closed so that the FDCP relay remains energized. This last relay maintains its "work" contact c closed, so as to maintain the maintaining circuit of the FTMDC relay.



   At the central station) when the OR relay has lost its excitation, at the start of the coordination pulse transmitted by the field station, the OAT, OBT relays of the periodic switching chain have already dropped to rest, practically at the same time than the analogue relays of the field station.



  The fall of the OR relay, causing the closing of its "rest" contact a, therefore energizes the OTMDC relay, the excitation circuit of the latter also comprising the "rest" contact d of the OAT relay and the "work" contact c of the OCT relay, the latter contact being closed at this time. Closing of the "work" contact c of the OTMDC relay completes a circuit, which was specified previously, to energize the ODCP relay; this -relay then closes its "work" contact c, so as to complete the holding circuit of the OTMDC relay. The OR relay being released, the closing of the "on" contact d of the OTMDC relay triggers the action of the OTC time chain of the OLC device, as explained for the command code.

   Although the "work" contact a of the ORP relay is closed, the open "rest" contact b of the OTMDC relay prevents the triggering of any periodic switching action by guaranteeing that the OAT relay remains not energized for the rest of the code d 'indication. At the same time, the "rest" contacts f and ± of the OTMDC relay prevent any operation of the telemetry receiver, retaining the indication which has been displayed, whatever it may be, until the indication code is finished.



   At the end of the coordination pulse, the OR relay is energized again and closes its "work" contact c, so as to switch the chain at OTC time to its normal position and then to command the reset action. zero.



  This occurs when the FR relay of the field station occupies its normal position, so as to initiate a normal reset action in the FLC encoder. When these operations have started, the OCT relay drops out at the end of its long drop period, which period is established at this time since the "rest" contact a of the OMSTP relay is closed. The OLBP relay "work" contact a is closed for sufficient time intervals, in combination with the delayed drop period of the ODCP relay, to keep it in the working position. When the OCP relay drops to idle, the central station circuits are prepared to receive the indication code at the end of the reset period. central station and field station coding devices.

   The OTP relay is kept energized by the "rest" contact c of the MSTP relay, so that the OR relay is continuously connected to the line circuit.



  As previously indicated, the operation of the periodic switching chain is prevented by the open "rest" contact b of the OTMDC relay. This relay completes the circuits, by its "work" contact d and e, so as to place the time and counting strings of the OLC coding device under the control of the OR line relay, which follows the code transmitted by the field station.



   The system remains in the condition which has just been defined as long as there are codes of the centralized control system to be transmitted. If a control code is stored during this period for transmission, the OMSTP relay is energized by the circuit comprising the "rest" contact b of the OST relay and the "work" contact a of the ODOP relay. At the appropriate moment, during the transmission of the various successive codes, the OM relay is energized, the circuit external to the coding device being completed by the "rest" contact a of the OST relay, the "rest" contact b of the relay OCT and the "work" contacts b of the ODCP and OMSTP relays.

   Taking into account the priorities established in such a centralized control system, the OLC coding device is actuated at the appropriate instant to control the OT relay, so that its "rest" contact repeats the code. The operation of this contact is repeated by the OTP relay, which transmits the code through its contact a;

  <Desc / Clms Page number 22>

 
At the end of the indication code, which triggered the transfer action, the FST relay has already been energized, so the FMSTP relay drops out after the cascade fall of the FM and FMP relays.



   Likewise, the FDCP and ODCP relays drop out after the end of the final code signal, when their circuits are interrupted at the "work" contact a of the corresponding repeater relay LBP. At each location, that is to say at the central station and at the field station, the TMDC relay drops out, because it loses its excitation due to the interruption of its holding circuit at the location of the "working contact". "c of the corresponding DCP relay. At the field station, the fall of the FTMDC relay again assigns the command of the FTPA relay to the a contact of the telemetry transmitter.

   At the central station, the fall of the OTMDC relay again leaves the control of the contact of the telemetry receiver to the contact b of the ORP relay, and also initiates the operation of the motor of the telemetry receiver. At this time, the transmission of the telemetry indication codes is re-established on the line circuit, in accordance with the operation previously described.



   It may happen that the field station and the central station simultaneously trigger the request for a centralized code. In other words, the OST and FST relays can drop off at about the same time, at least during the same time period when a telemetry code is cut. When the periodic switching relays drop out during the next telemetry code contact period, the device at each location, central station, and field station operates to. separately transmit for each location a coordination pulse as explained above. At the station, the coordination pulse consists of an open period of the line, while at the central station the pulse is transmitted as a bypass of the line.

   The device at each location activates itself to pass the TV code. measurement at the centralized control code. This action is entirely locally controlled, since the coordination pulses are not received at the opposite ends of the line circuits. The periodic switching relays CT of each location drop out at the same time, each with a short delayed drop-off period, under the influence of the open "rest" contact!:. of the local MSTP relay.



  Each line relay, that is to say each of the FR and OR relays, is brought back at the same instant under local control, respectively to its normal position and to its attracting position, so that the FLO coding devices and OLC simultaneously return to zero under these normal conditions. Each location being in the desired condition to transmit a code of the centralized system, the two codes, that is to say a control code and an indication code, are triggered and their first pulses are transmitted simultaneously. Under these conditions, one of the two locations enjoys priority and renders the other location inoperative.

   It suffices to note that, in the system shown here, the indication code has priority and the central station is rendered inoperative until such time as transmission of the indication code is terminated. At this time, transmission of the control code, which has been stored during this indication mode, can continue and end. Reference will be made to the previously mentioned publications for a complete explanation of this synchronization action.



     The system according to the present invention comprises various bypass devices to remedy faults which may arise. At the field station, a TMSP telemetry maintenance repeater relay has been shown. As long as the telemetry equipment at the field station is functioning properly and as long as the indication relays are energized to control the telemetry transmitter, the TMSP relay remains energized. If any fault occurs in the telemetry transmitter and associated indicating equipment such that telemetry codes are not transmitted, the drop of the TMSP relay energizes the FTMDC and FDCP relays.

   The excitation circuits of these last two relays appear evidently; they go through the "rest" and b of the TMSP relay. Closing of the "working" contact g of the relay,

  <Desc / Clms Page number 23>

 FTMDC bypasses the command exerted by contact.a of the remote measurement transmitter and keeps the FTPA relay energized. This action restores the line circuit and keeps it in this condition, so that the power of the line battery LB is supplied to the central station by the line circuit.



  Since the FTMDC and FDCP relays are kept energized, the station's FLC coding device can command the transmission of an indication code if the FST relay drops out. The circuit of the FM relay, circuit defined previously, is completed by the closing of the "rest" contact a of the FST relay, so as to trigger the operation of the FLC coding device. The FMSTP relay is energized in a similar manner and transfers control of the FTPA and FTPB relays to contact a of relay FT.



  The indication codes are then transmitted, as has already been explained, by the operation of contact a of the FTPA relay, the coding device being driven by the relay FR, since the latter is controlled by the operation of the contacts a and h from the FTPB relay. The transmission of the first indication code, a transmission which has not been shown or described in detail, must be coordinated in an appropriate manner so that the central station apparatus is in a condition to receive this code. The first code is transmitted immediately to indicate the fault and keeps the telemetry receiver unconnected until the fault has been corrected.

   As the FTPA relay is kept energized continuously, when no indication code is being transmitted, the line circuit is closed and control codes, transmitted by the central station, can be received by the FR relay and be recorded. by the FLC coding device.



   At the central station, an analogue OTMSP telemetry hold repeater relay is used. This relay is kept energized as long as a telemetry indication is recorded in the TMR receiver. If the telemetry receiver has a fault removing the indication, or if no indication has been received from the field station, the OTMSP relay is not energized and drops out.



  The push button PBP repeater relay is locally controlled by the conditions of such a fault, for example by a failure of the power supply, and can also be manually controlled by the operator. This relay is only energized if a fault occurs or if the operator closes a pushbutton circuit.The OTMSP relay, when it drops, transfers the system to the centralized control by continuously energizing the OTMDC and ODCP relays by obvious circuits, which are closed respectively by the "rest" contacts b and !! of the OTMSP relay.



  In this condition, if the OST relay drops out to trigger a control code, the OMSTP relay is immediately energized and its energization is followed by that of the OM relay as explained previously. The OLC coding device then operates to drive the OT relay, which itself drives, through its "rest" contact, the OTP relay according to a similar code. The operation of the contact a of the OTP relay, transmits the control code on the line circuit by alternately bypassing and restoring the line as already explained. The first code, which is transmitted immediately, must be coordinated in an appropriate manner and causes the remote measurement transmitter to shut down until the fault has been corrected.



   When the fault has been remedied, which caused the OTMSP relay to drop, it is necessary for the operator to return the system to normal operation; it suffices to activate the PBP relay by hand. Opening the "rest" contacts b and a of the PBP relay suppresses the energization of the OTMDC and ODCP relays if the centralized system is at rest. If these relays are kept energized by the transmission of a centralized code, their fall is delayed until the moment the code ceases. The fall of the OTMDC relay allows the telemetry code transmitted by the station to be received, and the recording of the indication in the TMR telemetry receiver again energizes the OTMSP relay, so that it attracts its contacts and returns the system to normal operation.



   From the previous explanations, on the operation of the system in the case of the existence of a fault, it is obvious that the operator can completely inoperate the telemetry system and separate it from the control circuit.

  <Desc / Clms Page number 24>

 line by initiating transmission of the appropriate control code and performing local manipulations. Under these conditions, the line circuit is continuously available to the centralized control system and no coordination is necessary before the transmission of a control code or an indication code.



   The system according to the invention thus achieves appropriate coordination between the two control systems, which share a common line circuit connecting the station to the central station. The periodic operation of the chain of periodic switching relays, during the transmission of the telemetry codes, makes it possible to synchronize the control of the change from telemetry codes to centralized control codes. The periodic switching period makes it possible to transmit coordination pulses in either direction on the line circuit, so as to simply and directly initiate the transfer operation.

   The coordination pulse makes it possible to correctly operate the centralized control devices at each location (central station and station) and to prepare them simultaneously for the transmission and / or reception of a code, so that the centralized codes are correctly transmitted and received by the system. This action is automatic and does not require any monitoring from the operator. At the end of a centralized system code transmission period, the return of each location to a condition, in which the telemetry codes can be transmitted over the line circuit and can be received correctly, is also automatic and is carried out without any manual action.



   The system according to the invention therefore constitutes a relatively simple and economical device making it possible to coordinate two systems so that they can jointly use a single communication channel. At the same time, the codes of the two systems are correctly separated so as to avoid interference and incorrect actions.



   Only one embodiment of the coordination circuits according to the invention has been described and shown here, but it is understood that various modifications can be made to this embodiment, without departing from the scope for this. of the invention.


    

Claims (1)

ABSTRACT. Installation of centralized coded control and coded telemetry, characterized by the following main points considered individually or in combination. 1 - It comprises a communication channel, connecting a first location and a second location, a first control system, which continuously transmits periodic cycles of coding from the first location to the second location, a second control system, capable of transmitting to cer - at certain moments of the codes in one or the other direction, between the first location and the second location, a connection circuit at each location, to normally link the first control system to the communication channel, a control device transfer, capable of transferring said connection circuit from the first control system to the second control system, so as to transmit the codes of the second system on said channel, the transfer device comprising, at each location, a periodic switching device which periodically responds to the operation of the first control system, and a relay pulse device which, when actuated, acts to transmit a coordination pulse to trigger the operation of the transfer device, each pulse device being actuated, in response to the operation of the periodic switching device, when a code of the second system is stored at the corresponding location for transmission. 2 - The first system is a normally active telemetry system which transmits periodic cycles of indication from the first location to the second <Desc / Clms Page number 25> location, and the second system is a centralized control system. 3 - The installation comprises a remote control system which includes a transceiver at each location to transmit the codes controlling the receiver of the other location, a periodic switching device responding to the operation of the telemetry system to open a periodic switching period during the transmission of a telemetry indication, a pulse device installed at each location and responding to the operation of the periodic switching device only when a control system code is stored at the corresponding location for transmission, this pulse device transmitting a coordination pulse during this periodic switching period, a relay transfer device arranged at each location and responding to each coordination pulse, so as to transfer the connection circuit from the corresponding location to connect the corresponding transceiver to the communication channel and to remove the connection of the telemetry system, so as to allow the transmission of the stored code of the control system * 4 - The first location is a field station and the second location is a central centralized command post. 5 - The installation comprises a relay transmission device, arranged at each location and connected to the channel, a circuit normally connecting the said device of each location, so as to allow the transmission of the codes of the telemetry system on the channel, and a pulse re-device at each location for controlling the transmitting device to transmit a coordination pulse. 6 - The installation comprises a centralized control system, which includes at each location a code transceiver, capable of transmitting codes at certain times to control the receiver of the other location, and a contact for normally open start, which only closes if a code is stored for transmission, a connection circuit at each location to normally connect the telemetry system to the line circuit, each connection circuit including a transmitter contact. code, which is interposed in the line circuit and repeats any code transmitted to the corresponding location so as to transmit this code on the line circuit, a chain of periodic switching relays at each location, this chain being able to respond to each telemetry indication cycle and being able to open a periodic switching period of a predetermined length during each telemetry indication cycle a pulse device at each location to control the corresponding contact of transmitter and transmit a coordination pulse on the line circuit only when a code of the centralized system is stored at that location, each pulse device comprising successive contacts of the relays of said chain during said switching period. - periodic station and the corresponding start-up contact, a relay transfer device at each location, this device being able, when it is energized, to transfer the connection device of the line circuit to do so, switch from the telemetry system to the centralized control system, said transmitter contacts being able to repeat a code of the centralized system which has been transmitted by the corresponding transceiver, and an excitation circuit for each control device. transfer, this circuit comprising a contact, which is closed in response to the transmission of a coordination pulse, from either location, and other contacts forming part of the periodic switching relays. that and closed in series during the said period of periodic switching, each transfer device being kept energized during the operation of the corresponding transceiver. 7 - A coordination circuit, making it possible to use a common communication channel for a first coded remote indication system and for a second analogous system, comprises a transmitter relay, controlled by certain <Desc / Clms Page number 26> times by the first system and at other times by the second system, a periodic switching circuit responding to the operation of the transmitter relay when it is controlled by the first system, so as to periodically open a coordination valve, a relay starting repeater, an excitation circuit, for said relay, this circuit being completed by the periodic switching device when the coordination valve is open and if a code is stored by the second system, a circuit which comprises a contact in the energizing position of said repeater relay and a coding contact of the second coded system, this circuit responding at certain times to the operation of the periodic switching device so as to control the transmitter relay and transmitting a coordination pulse, the second control system being actuated, in response to the transmission of the coordination pulse, to keep said repeater relay energized and to control the emitter relay by said control contact. coding. 8 - The coordination circuit includes a transmitter repeater relay and a pulse circuit, which comprises a contact in the excitation position of the starting repeater relay and a normally closed contact forming part of the second system, this contact according to the code, this pulse circuit also responding to the operation of the periodic switching device, during the valve opening period, to control the transmitter repeater relay and to transmit a coordination pulse, a relay disjunction device , excited in response to the transmission of the coordinating impulse and acting, when it is. excited. to actuate the second system and to-. render the first system inactive, the second system being able, when it is active, to actuate said code follower contact so as to control the transmitter repeater relay, to transmit the stored code of the second system, and to keep the start repeater relay and the cut-off device energized until the stored code has been completely transmitted. 9 - The coordination circuit comprises a starting repeater relay which normally occupies a first position and which can pass to a second position when the coordination valve is open, provided that a code of the second system is stored, in view to be transmitted, a code transmission device, which responds at the same time to the operation of the periodic switching device and to the starting repeater relay in its second position, to transmit a coordination pulse on the communication channel, an excitation circuit of the relay disconnection device, this circuit comprising a contact which closes in response to the transmission of the coordination pulse, and contacts of the periodic switching device, which are closed during the period of opening of the coordination valve, and a holding circuit capable of keeping the relay circuit breaker energized until the moment when the second system has finished transmitting its code. 10 - The coordination device comprises a periodic switching device, which responds to the normal operation of the first system so as to periodically carry out a coordination period, a starting repeater relay, which is not energized during the said coordination period only if the operation of the second system so requires, a pulse circuit, which comprises contacts, controlled by the periodic switching device, and a contact in the energizing position of the starting repeater relay, this pulse circuit being operative during the coordination period when the start repeater relay is energized to transmit a coordination pulse, a trip relay, energized in response to the transmission of the coordination pulse, and a circuit transfer, which comprises other contacts of the starting repeater relay and contacts of the disjunction relay, this transfer circuit acting at certain times to transfer the connection circuit from the first system to the second system. <Desc / Clms Page number 27> 11 - The coordination device comprises a connection device, normally connecting the first system to the communication channel, a chain of periodic switching relays, which only acts in response to the transmission of a code from the first system., this chain periodically inserting during operation a period of coordination in the transmission of a code of the first system, a starting repeater relay and an excitation circuit of this relay, this circuit comprising contacts of the periodic switching relays , which are closed in series only during the coordination period, and a contact which is closed only if the operation of the second system requires it, a pulse circuit, which includes a transmission repeater relay, a contact in the energizing position of the starting repeater relay and other contacts of the periodic switching relays, this pulse circuit being able to transmit at certain times a coordination pulse during the said coordination period, a tripping relay and excitation circuits of this relay which include a contact which closes in response to the transmission of the coordination pulse, and a transfer circuit, which includes other contacts of the starting repeater relay and contacts of the trip relay, this transfer circuit acting at the same times to trigger the operation of the second system and to transfer the connection circuit from the first system to the second system. 12 - The coordination device comprises a pulse circuit, which itself comprises a contact in the energizing position of the starting repeater relay and other contacts of the periodic switching relays, this pulse circuit being able to command certain moments the transmission repeater relay, so as to transmit a coordination pulse during the coordination period. 13 - The coordination circuit comprises a transmission repeater relay, which comprises a contact, interposed in the communication channel or line circuit, and controlled normally to allow the transmission of the coding cycles of the telemetry system, a pulse circuit, which comprises the winding of the transmit repeater relay, a contact in energizing position of the start repeater relay, a normally closed coding contact of the centralized control system, and contacts of the relays switching cycles, which are short-circuited only during the switching period, the pulse circuit being able to control the transmit repeater relay so as to transmit, at certain times, a coordination pulse to the relay circuit. line, during the switching period, and at other times codes emitted by the centralized system, a trip relay and an energizing circuit of this relay, this circuit comprising a contact, closed in response to the transmission of the. coordination pulse, and other contacts of the periodic switching relays, which are closed in series only during the switching period, the disconnection relay, when energized, being able to trigger the operation of the centralized system and interrupting the transmission of the telemetry coding cycles, said normally closed coding contact controlling the transmission repeater relay in accordance with the operating code of the centralized system.