RU2540812C1 - Method of information exchange in telemechanics system - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: method of information exchange in the telemechanics system is provided, in which any information message is framed by signs of its beginning and end, and between them there are fields of codes of address, control and information forming the transmitted polynom, and protective control code sequence, to avoid the appearance of a false code "flag" the signal "0" is inserted in the transmitted message after the transfer of five consecutive signals "1", the "1" signal at high order of the first byte of the address code is a sign of the use of two-byte address, and the signal "0" is the sign of single-byte address structure. Information message is preceded by the transmission of sync byte "meander" of alternating signals "1" and "0", the control station periodically transmits the message to the communication channel - the centralised polling of readiness to transmit information of all controlled points, the code is entered to the address field of the message of the centralised polling, that is different from the code of addressing of the controlled point, and the information field is divided into equal parts, the number of which is equal to the number of controlled points, each of which on the corresponding section transmits the sign of readiness or un-readiness to transmit information in the form of pairs of signals "10" or "01". The number of pairs of signals on each section corresponds to an integral ratio of frequency of data transmission from the most remote and the given controlled point.

EFFECT: increase in informativeness and operational efficiency of telemechanics system.

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Description

The invention relates to methods for generating information messages in telemechanics systems using trunk communication channels and implementing the functions of telecontrol, tele-signaling, telemetry, diagnostics and testing of control points and controlled points of objects of railway transport, industry, energy.

A known method of generating information messages according to the protocol of the channel level HDLC (high level data link control) according to the standard ISO 13239 [1]. In accordance with the standard, an informational message is framed by signs of its beginning and end - bytes of the “opening” and “closing” “flags” with the structure 01111110, between the “flags” are the fields of the address, control, information and protective control code sequences covering the data of the components, placed between the flags. The appearance of a false code “flag” in the information message is eliminated by inserting the signal “0” into the transmitted message after five consecutive signals “1”, and in the receiver, when monitoring the received information message, the signal “0”, recorded after five consecutive signals “1”, deleted. Signal “1” in the high order of the first byte of the address field code is a sign of using a two-byte address, and signal “0” in the indicated bit is a sign of a single-byte address structure. The type of message is determined by the code structure of the control field. The information field includes data whose type is specified in the control field.

The pauses between the transmission of information messages are filled with “flags”, the first byte, different from the “flag”, is a sign of the beginning of the transmission of the message, and the first byte of the “flag” after the transmission of bytes other than the “flag”, is the sign of the completion of the transmission of the information message.

The introduction of "flags" as signs of the beginning and end of an informational message eliminates the need to indicate the length of the message and ensures synchronization of information exchange points.

The disadvantage of this method is the transmission of "flags" also to fill in the gaps between the transmissions of information messages, which excludes the possibility of using one half-duplex communication channel for information exchange between the control point (PU) and the controlled point (CP). In addition, when using the known method for conducting information exchanges of controllers with several controllers, the data transfer rate should be set the same for all controllers regardless of their distance from the controllers and correspond to the maximum possible data rate from the most remote controllers. These shortcomings reduce the information capabilities and the efficiency of the telemechanics system.

Closest to the proposed one is a method of generating information messages according to RF patent No. 2236706, in which the transmitted message contains the following components: number of bytes of information, sign of line identification, address of the receiver and sender of information, type code of the information parcel, information field, parcel generation time and control code [2].

The known prototype method allows for information exchange of a control center with a number of controlled points due to the presence of sender and receiver points in the parcel. The disadvantage of this method is the lack of components to synchronize the operation of remote locations in the pauses between the transmission of information messages and, as a result, the inability to use the main communication channels in the telemechanics system.

The objective of the invention is a method for generating informational messages, providing the use of one half-duplex backbone communication channel for exchanging informational messages between the control rooms and a number of controllers, with each of which information exchange is carried out at the speed maximum possible for each controllers and, accordingly, increasing the efficiency of information exchanges in telemechanics systems .

This is achieved by the fact that any information message according to the ISO 13239 standard for telemechanics systems that use a trunk communication channel to connect a control point to controlled points, in which any information message is framed by signs of its beginning and end - bytes of the “opening” and “closing” “flags” "With the structure 01111110, between the" flags "are the fields of the address, control and information codes that make up the transmitted polynomial, and the protective control sequence of the code that corresponds to the atku transmitted by dividing the polynomial by the generator polynomial the structure 2 ¹⁵ +2 ¹² +2 ⁵ +1 to exclude the appearance of false code "flag" is inserted into a transmitted message signal is "0" after five successive transmission signals "1", the inserted signal " 0 ”is deleted by the receiver, the signal“ 1 ”in the high order of the first byte of the address code is a sign of using a two-byte address, and the signal“ 0 ”in the indicated bit is a sign of a single-byte address structure, preceded by the transmission of the synchronization byte of the“ meander ”from alternating with of the “1” and “0” signals, the control center periodically transmits a message to the communication channel — a centralized survey of readiness to transmit information of all controlled points, and the specified message is transmitted at a minimum frequency equal to the frequency of data transmission from the controlled point farthest from the control point, a code is entered in the address field of the centralized survey message that differs from the address codes of any controlled point, and the information field is divided into equal sections, the number of which is equal to the number of monitored points, each of which in the corresponding section transmits a sign of readiness or unavailability to transmit information in the form of pairs of signals “10” or “01”, and the number of signal pairs in each section corresponds to the integer ratio of the data transmission frequencies from the most remote and given controlled point; after analyzing the data obtained during the centralized interrogation cycle of the controlled points, the control point transmits to the controlled point that has transmitted a sign of readiness to transmit information, the message is an information call command, and the frequency of the information call command transmission corresponds to the data received earlier from the called controlled point, and in response to a call command, the controlled point at a frequency acceptable for it transmits a message in the corresponding fields of which the address of the source point is entered, data type, information and code check sequence; the number of consecutive messages - information call commands and response messages from monitored points corresponds to the number of monitored points from which the sign of readiness for transmitting information was transmitted at the stage of centralized polling.

Figure 1 shows a diagram of a multi-level telemechanics system in which the controlled items KP-1 ... KP-P are connected to the main communication channel with a common control unit. In telemechanics systems for railways, the length of the main communication channel can reach 150-200 km, and the values of resistance, inductance and capacitance of sections of the communication channel from control panels to different control gears can differ by tens of times. The indicated parameters of the communication channel sections also determine the possible data transfer rate by different controllers.

Figure 2 and figure 3 shows the timing diagrams explaining the proposed method of forming information messages. Information exchanges are divided into the stage of centralized interrogation of the readiness for data transmission by each control unit and one or several stages of information exchange of the control unit with the control unit, from which a sign of readiness to transmit information was received.

A distinctive feature of the proposed method is the replacement of "flags", which in ISO 13239 completely fill in the pauses between the transmission of information messages, on single-byte "meanders" ("M"), consisting of alternating signals "1" and "0" and preceding the transmission of messages from PU and KP. Due to the presence in the “meander” of the maximum number of transitions from “1” to “0” and from “0” to “1” for a relatively short period of time, synchronization of the operation of the PU and KP devices is ensured. When replacing continuously transmitted “flags” with short “meanders”, pauses are formed which are used to transmit information messages from the CP through one half-duplex communication channel. As a result, the information capabilities of the telemechanics system are increasing.

In the proposed method, in accordance with ISO 13239, any message from the PU and KP is framed by “opening” and “closing” “flags”.

Following the “opening flag”, the address code KP (AKP) according to ISO 13239 can be single-byte or double-byte. A two-byte automatic gearbox is used if more than 127 gearboxes are included in the telemechanics system. A sign of the use of double-byte addressing is the signal "1" in the high order of the first byte of the address. For centralized polling, a code is used as the IP address that is not used to indicate the address of any KP. In the example shown in Fig. 2, the code for the address field, consisting of signals “1”, is used for centralized polling.

The type of data being transmitted or requested is determined by the control field code (“U”).

The control field is followed by an information field. In the proposed method, the information field of the stage of a centralized survey of KP (Fig. 2) is divided into "n" equal parts for "n" KP. KP number corresponds to the number of the selected part of the information field. Since all CPs are synchronized by the meanders transmitted from the control unit, each control unit determines the time interval of “its” part and within it transmits a sign of the presence (or absence) of data for transmission to the control unit.

All message components between the “flags”, as in ISO 13239, form a transmitted polynomial that is protected from distortion by a two-byte code check sequence (PDA). CPC corresponds to the remainder of the division of the transmitted polynomial by the generating polynomial, which, as in ISO 13239, is equal to code 2 ¹⁵ +2 ¹² +2 ⁵ +1.

Message - a centralized poll of the control unit is formed by the control unit and transmitted to the communication channel at the minimum speed corresponding to the data transfer rate from the most remote control unit. This ensures the normal reception of a centralized polling command by all CPs regardless of their removal from the control panel. A distinctive feature of the proposed method is the transmission on the allocated for each KP of the information field sign of the presence (absence) of data for transmission at a speed corresponding to the capabilities of this KP. The centralized polling stage is completed (in accordance with ISO 13239) by transmitting the PDA and the “closing flag”, after which the transmission of the synchronization combination -10101010 (“meander”) from the control unit is resumed. PU analyzes the code combinations accepted in the information field from all CPs; by the type of signal combination in all areas, both the permissible information exchange rate with each control unit and the presence (absence) of data for transmission are determined.

Upon receipt of signs of lack of data for transmission from all the control rooms, the control center may repeatedly carry out the stage of centralized questioning of the control center or forcibly request any data from the selected control center.

If there is data from the CP, the CP carries out one or several stages of information exchange with the CP, which transmitted the corresponding sign at the stage of a centralized survey. If the sign of the availability of information is received from several control units, the control unit carries out the alternate stages of information exchange with these control units, and the exchange order is determined by the established priority of the control unit.

For example, figure 2 shows that each CP is allocated two bits (bits), and to increase noise immunity, data from the CP (a sign of the presence or absence of data for transmission to the control unit) is transmitted by a correlation code. Code “10” corresponds to the readiness of the CP to transmit information, and code “01” to the lack of data for transmission. Code “00” is a sign of a malfunction or lack of an appropriate gearbox. If for the CP the maximum possible speed corresponds to the transmission rate from the message center of the centralized polling of the CP, the combination of "10" or "01" on the corresponding section of the information field is transmitted once (in figure 2, such a combination is transmitted CP (n-1) and CPP). For KP13, KP14 and KP15 (in the above example), the permissible transmission rate is twice the minimum, therefore for a CP of this type in two bits of the code the combination of signals “10” or “01” is repeated twice, i.e. Signals "1010" or "0101" are transmitted to the communication channel. For KP1 (in the example shown in Fig. 2), the permissible transmission rate is four times higher than the minimum, therefore, for this type of KP, the code combination is repeated four times, i.e. Signals “10101010” or “01010101” are transmitted to the communication channel. Without changing the essence of the proposed method, the length of the sections for transmission from the CP signs of the presence or absence of information and the permissible data rate may be different.

In the given example, the signs of the availability of data for transmission to the control room are signals “10” received from the control unit (n-1), signals “1010” received from the control unit 15, and signals “10101010” received from the control unit 1, and signs of the lack of data for transmission in the PU-signals "01" received from KPP, the signals "0101" received from KP13 and KP14.

Figure 3 shows an example of information exchange with KP15, from which at the stage of a centralized survey received a sign of the availability of information for transmission to the PU. The data transfer rate is determined by the type of code received from KP15 at the stage of centralized polling. In the given example, the speed of information exchange is twice as high as the minimum. As shown in figure 3, after the transmission of the synchronizing "meander" and "opening flag" PU transmits codes AKP-15 (00001111) and the code of the control field. In the above example, for the code - the command to call data from the CP, a combination of signals 1110 is used. The transmission of a message from the control unit is completed by the PDA and “closing flag” codes. In response to the selected CP (KP15 in the above example), at the speed determined in the centralized polling cycle of the KP, the automatic transmission (in the given example, the code is 00001111), the code of the field U corresponding to the type of information transmitted (code 1010 in the given example) and the data (the code is 101111110011011x ... in the above example). In accordance with ISO 13239, an additional bit “0” (bit stuffinq) is introduced into the data field code after five consecutively transmitted “1” signals to prevent the formation of a “false flag”. A similar bit “0” is inserted between two bits of the code of the field U, since five consecutive signals “1” were recorded in the transmission section of the codes of the automatic transmission and U. The inserted bits “0” are highlighted in dashed in FIG. 3.

The message is completed with the PDA and “closing flag” codes.

Similarly, information exchanges are conducted with other CP KP, and the speed of each information exchange corresponds to the maximum possible for KP, with which data is exchanged. Similar messages are generated by the control center for transmitting telecontrol commands to the objects of controlled points.

Consider the effectiveness of using the proposed method for generating information messages for the following telemechanics system:

- the total number of KP in the telemechanics system is 40,

- for 31 ... 40 KP data transfer rate is equal to F,

- for 21 ... 30 KP, the data transfer rate is 2F,

- for 11 ... 20 KP, the data transfer rate is 4F,

- for 1 ... 10 KP, the data transfer rate is 8F,

- each CP transmits an informational message with a length of 20 bytes (160 bits).

In the calculation, the length of the “meanders” preceding the transmission of each informational message, as well as the bit stuffinq, are not taken into account due to the insignificant effect on the total transmission time.

The length of the stages of a centralized interrogation of KP and information exchange of KP with PU is determined by the time diagram of Figs. 2 and 3. For this example, the length of the stages is 128 and 256 bits, respectively. When using the same speed F for the transmission of data for all CPs, the time for collecting information from all CPs (T _TOTAL ) will be equal to:

and when transmitting data at the individual speeds indicated in the example for each CP group, the time for collecting information (T _IND ) will be:

It is seen that the time for collecting information when using the proposed method is more than halved, i.e. the efficiency of the telemechanics system is doubled. It is obvious that with an increase in the number of CPs that can conduct information exchanges at a higher speed, the effectiveness of the proposed method increases. So, for example, with the number of CPs conducting information exchanges with PU at speed F equal to 10, and at speed 8F equal to 30, the ratio of T _TOT and T _IND will be large 3.

It is shown that the proposed method allows information exchanges between the controllers and a number of controllers on one half-duplex trunk communication channel and use the maximum possible speed for transmitting data from each controllers. This provides an increase in the information content and efficiency of the multi-level telemechanics system.

Information sources

1. Protocols of information and computer networks: Directory / S.A. Anichkin, S.A. Belov, A.V. Bershtein et al .; Under. ed. I.A. Mizina, A.P. Kuleshov. - M.: Radio and Communications, 1990. - 504 p.: Ill.

2. RF patent for the invention No. 2236706, 2004 - prototype.

Claims (3)

1. The method of information exchange in a telemechanics system that uses a trunk communication channel to connect a control point with controlled points, in which any information message is framed by signs of its beginning and end - bytes of the “opening” and “closing” “flags” with structure 01111110, between flags ”are the fields of address, control and information codes that make up the transmitted polynomial, and a protective control sequence of the code that corresponds to the remainder of the division of the transmitted polynomial by Braz polynomial structure 2 ¹⁵ +2 ¹² +2 ⁵ +1 to exclude the appearance of false code "flag" is inserted into a transmitted message signal is "0" after five successive transmission signals "1", the inserted "0" signal is removed by the receiver, the signal A “1” in the high order of the first byte of the address code is a sign of using a two-byte address, and a signal “0” in the indicated bit is a sign of a one-byte address structure, characterized in that the information message is preceded by the transmission of the synchronization byte of the “meander” from alternating With the signals “1” and “0”, the control center periodically transmits a message to the communication channel — a centralized survey of readiness to transmit information of all controlled points, and this message is transmitted at the minimum frequency equal to the frequency of data transmission from the controlled point farthest from the control point , a code different from the address code of the controlled item is entered into the address field of the centralized poll message, and the information field is divided into equal sections, the number of which is equal to the number of controls uemyh items, each of which corresponding portion transmits feature availability or unavailability of the transmission media in the form of pairs of "10" signals or "01", the number of pairs of signals in each section corresponds to an integer ratio transmission frequency from the most remote and a given controlled item. 2. The method according to claim 1, characterized in that after analyzing the data obtained during the centralized interrogation cycle of the controlled points, the control point transmits to the controlled point that has transmitted a sign of readiness to transmit information, the message is an information call command, and the call command transmission frequency the information corresponds to the data received earlier from the called controlled point, and in response to a call command, the controlled point at a frequency acceptable for it sends a message to the corresponding fields which The address of the source point, the type of data, information and the control sequence of the code are entered. 3. The method according to claim 2, characterized in that the number of consecutive messages - commands to call information and response messages from monitored points corresponds to the number of monitored points from which the sign of readiness for transmitting information was transmitted at the stage of centralized polling.

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