NO801810L - AUTOMATIC RECORDER FOR CALL DATA - Google Patents

Description

The present invention relates to automatic registration and retrieval equipment for use in, or in connection with, a manual switchboard or a manual operator terminal for operating an automatic telecommunications exchange.

In recent years, the ever-increasing use of processor control in telephone exchanges, plus the expansion of dialing with dial-in and remote dialing, has reduced the volume of telephone calls that have to be set up with operator assistance. However, a significant number of such calls still remain, and there will certainly still be a need for a certain number of such calls for the foreseeable future. The current practice is that such calls are made while the operator prints out individual information manually for each such call. These notes are collected and calculated in a central location, before the bill is sent out.

Such a manual system is expensive and requires a lot of time, especially when it is surrounded by an increasingly automated system.

The purpose of the present invention is therefore to provide a device to provide the most automatic and otherwise as easy as possible registration and retrieval of data regarding manually operated calls, without the system being burdened with the above-mentioned disadvantages.

This is achieved by designing the automatic registration and retrieval equipment in accordance with the disclosure requirements set out below.

The present invention includes a command center with a mini processor and various storage devices with large capacity,

as well as a group of operator terminals connected thereto, each with its own microprocessor, buffer storage, display screen and keyboard.

Such apparent wastefulness when it comes to the use of computing power when using processors both in the central office and terminals,

is not necessarily particularly expensive, as relatively cheap processors are used. The relevant processors in the event

which will be described below are microprocessors in the operator terminal and a miniprocessor in the common command center or control unit. For this reason, the equipment is quite affordable. It is also constructed in a way which is advantageous, as will be seen later, so that, if a serious error occurs -in the command center, then each operator terminal can continue to

work for a certain time This time runs until the buffer stores at the operator terminals are full. When this happens, an indication of this is given to the operator, who returns to manual registration until the command center is repaired, or he finds the information from the buffer storage and registers it further manually, after which the operator's terminal can be fully used again until the buffer storage is full again .

In order to provide a clearer understanding of the present invention, it will now be described with reference to the accompanying drawings, where: fig. 1 shows a block core for an automatic registration and retrieval device according to the present invention,

fig. 2 shows a block diagram of an operator terminal as shown in fig. 1,

fig. 3 shows a block diagram for the software used in an operator terminal as shown in fig. 2,

fig. 4 is a block diagram showing the duplication of the processors in the command center (also called the control equipment),

fig. 5 is a somewhat more detailed block core for the double switch used in fig. 4,

fig. 6 is a block kernel for the command center software.

Fig. 1 shows an automatic recording device for call data

in a switchboard with several operator terminals POSI to POS96, which is served by duplicated, common control equipment in the command center, where system A is normally actively connected, and system B is in a standby state. The operator terminals or operator desks, as they are also called, are connected in groups to a number of data lines LI to L32, which connect the terminals to the common control equipment. If the common control equipment is located far from the operator terminals, these data lines may include a modem, and this is indicated in the figure with small crosses on the lines.

This means that in such cases each data line serves several operator terminals and is connected via a modem to the line of the common control equipment, and that this line is further connected to the operator's desk via another modem.

Each operator desk is assigned a microprocessor, which works completely independently of the processor in the common control equipment, so that when the common control equipment is exposed to a fault condition, the operator desk can continue to function while the common control equipment is repaired. Consequently, an error that may occur in an operator's desk does not render the entire system inoperative. The common control equipment also includes a processor that is larger and more powerful than the microprocessors at the operator desks. In the present case, the operator desks use the SBC80/30 microprocessors from Intel, while the common control equipment uses a PDPll-34 A from Digitel Equipment Corporation. The common control equipment acts as a data collector and data concentration medium for call registrations, and as a database for storing information that is common to several operator desks and is accessible from several operator desks.

Each of the two common control equipment systems comprises the above-mentioned processor .1, and to this is arranged a monitoring printer and a keyboard 2. At the line side of each system (A and B) there is an operator desk interface which connects the lines Li - L32 to the common control unit, and it will be seen that all these lines are connected to both interfaces 3. Furthermore, these interfaces are mutually connected via the connection 4, which includes turning arrangements (not shown) which will be discussed below.

Each system (both A and B) also comprises eh block 5 of multiplexers, and above these the interface is connected to a single two-way connection (known as unibus) to the processor. This block 5 acts as a multiplexer for one direction of transmission and a demultiplexer for the opposite direction of transmission.

Assigned to the processor, one also has a disk storage 6, which is a storage volume distributed over many disks, and this can be used as a buffer storage for call details and/or as a storage for commonly available information as mentioned above. In addition, a magnetic tape storage 7 is used, on which the final registrations can be made. Thus, the unit 7 can be remote from the rest of the system, especially when the system includes modems, such as e.g. for connections between the operator's desk and the common control unit.

Each operator desk has a panel with a keyboard for viewing call details, plus a dial pad or push button set for dialing. There is also display equipment as well as other visual equipment and possibly also alarms. The maximum number of operator desks that can be served by a single common exchange is, theoretically, 480, but in practice this figure is unlikely to be achieved, as the traffic capacity of the lines between the operator desks and the common control unit would probably be exceeded.

Thus, the complete system consists of a variable number of operator desks connected to a common control equipment which includes an auxiliary processor, and which is usually duplicated. With two such common control devices, one is usually active, while the other is in standby mode. The active auxiliary processor operates all operator desks, prints bill lists and provides data/time and database information. If the active processor fails, an alarm is triggered, and a manual switch can be actuated to activate the other processor. The system then continues with normal operation while the faulty equipment is repaired. Other forms of redundancy techniques can be used, e.g. the two systems can be used alternatively or alternately for fixed periods, while one processor takes over all the work when the other fails.

As already indicated, the operator desks are called cyclically under the control of the processor, such as 1 in the active common control equipment (system A), and when this request finds an operator desk with a call registration ready for dispatch, the call stops. Each of the operator desks on a common channel is identified by a special address number, and during the cycle, to this channel, all the terminals are called or asked if they have call data for registration. Communication takes place in a half-duplex manner with messages in both directions.

A message from the common control equipment to an operator desk contains the operator desk number in the title, and this message is received at all operator desks, but is only answered by the desk whose address is in the message header. Such a ppprops or polling technique is of course well known. Transmission of messages from the operator's desk is, as will be seen below, controlled by Jjelle's control equipment. Thus, when an operator desk is called, that position will respond with a message containing call records and details thereof in its buffer store, or if the buffer store is empty, with a "no-call" message. In the case of the control equipment, the absence of a response from a summoned operator desk is interpreted as an error condition, and reported to the control equipment''"" the board's monitoring recorder 2. '.

All messages in an arbitrary direction contain digit and block parity components that are checks on the receipt of the messages, and the control unit responds to a message with a positive or a negative statement, depending on whether the check operation succeeds or fails. In response to a negative statement, the source of the questionable message repeats the relevant message, and this continues until the message has been correctly received and received a positive statement. Alternatively, the system can be arranged to give a false alarm when a certain predetermined number of negatives are reached

statement has been received.' This may follow established practice in fault detection qg. correction implementation ,v Note that all call details are stored in the operator desk

and not in the common control equipment so that errors in the latter do not affect calls in progress. The common control equipment does not receive call details until they are transmitted from the relevant operator's desk, and upon receipt of these details, the moment equal to these is transferred to the calculation equipment - tape unit 7. in the present system. Thus, calls that are in progress can still be processed, and new calls can be set up under operator control, despite errors in the common control equipment. Thus, the main effects of an operator desk not being able to communicate with the common control equipment will be:

a) The operator desk is unable to send out call details

to the common control unit for transferring these to the load equipment, so that a queue of such registrations accumulate<x>" in the operator's buffer storage. This can fill the buffer storage, and

t in this case the display screen will show a message,. which prompts the operator to return to manual processing or empty the storage. b) The operator's desk is unable to carry out other transactions.

.. tions, which in the present system may include processing of

ordered or delayed calls and certain special usage possibilities. This will be an inconvenience, but will not represent any adverse impact on normal operations that do not require access to the database.

Errors on an operator desk will of course only affect the

the calls served at this desk.

Fig. 2 is a block diagram showing the most important elements

which is included in the set-up at an operator's desk, where the position control unit is a microprocessor which with associated circuit elements such as its program memory and the buffer storage is produced by

block 10.

The connections to the operator's switching equipment include e.g.

an output pulse train unit 11 which is connected to an interface 12,

which itself is connected to the processor block 10, and also to a further interface 13 and USART 14. The latter is also

a cross-sectional unit. The interface 13 is connected via a display. interface 15 to a display screen 16 at the operator's desk. Thus, signals from the processor or from the common control equipment can be presented to the operator in the same way as visible indications of digits and other signals sent from the operator's panel.

The USART is connected via two amplifiers, one for each transmission direction, to a CPU interface 17, and this gives the operator desk access to a line to the auxiliary processor at the control equipment.

Such an interface is necessary to customize the information

from USART 14 to the line states on the data line and can, as already mentioned, include a modem if the line to the control unit is long.

As far as interface 12 is concerned, this is also connected to the operator's switching network over high-impedance monitors for the keyboard or for other switches shown as a block 18. This connection includes outputs consisting of control signals via a 6-bit, address for selecting which monitor is to be read. , and an 8-bit output that provides the voltage detected by the monitor. In addition, the monitor unit has a clock input 19 which is derived directly from the processor's clock system in block 10.

The data bus 21 of the processor 10 is also equipped with a multi-bus interface (24), which is normally used to expand the information content of the data bus, and in this particular case it is used to provide additional inputs and additional outputs. times from the processor for reading information from the operator keyboard 26 and the illuminated indicators (LED) 27. Note that the monitor points discussed are represented by telephone subscriber lines. These connections include a control connection 19 and connections over two-way bus driver circuits 20. The other connections include data bus connection 21 between the interfaces 12, 13 and 14 and the processor; the read/write connection 22 and a selector connection 23. The monitors 18 are controlled by clock pulses, and the clock pulses used are the system's own clock pulses, which . is also used to control the data bus connection 21. The connections 21, 22, 23<*>make it possible for the processor to control all functions on the operator desks, and many of these have already been discussed in connection with fig. 1.

We will now briefly describe the software structure for an operator desk and how this is divided into various "Tasks". In this connection, reference will be made to fig. 3. It must be noted that a large part of the applied software, like too much of today's software!. is built up in modular form. Note also the great functional and operational similarities between a software module and* its hardware equivalent.

Communication and Interruption Task 30 controls the dispatch

and the reception of all messages from the control equipment, and all internal processor messages within an operator desk. Thus, it receives messages from the auxiliary processor at the control equipment, indicates an interrupt signal to the processor at the operator desk so that it can handle such messages, and sends back an acknowledgment to the auxiliary processor. If a message is correctly received, it is decoded (taken out of format) and passed on so that it can be processed by Equipment and Diagnosis Task 31. •

Equipment and Diagnostic Task 31 has two purposes: Operation of normal, call and diagnostic programs. The normal call handling program handles all traffic at the operator's desk, such as providing equipment for ordinary calls, emergency calls, mobile calls,

etc. as required by the users of the system. The diagnostic programs provide a series of simple diagnostic tests that are performed on the operator console hardware to check that it is functioning correctly.

The next Task to be performed is the line's loading job 32, which is the first phase you enter after start or repeated start. During this phase, the program to be executed during normal operation is read into the operator console's memory from the auxiliary processor. The programs that are loaded can be normal operating programs or diagnostic programs for use by maintenance engineers to check the system's operation.

Hardware Scan Task 33 scans the switchboard's monitoring points and panel switches for input signals and sends messages to Equipment Task 31 as soon as call information is detected. This reference to sending messages means in this text that Task 31 is put into practice, which emphasizes the relationship between hardware and software in the blocks shown in fig. 3. This Task 33 also controls the conversion of the monitored signal from a voltage change to a logical signal such as start call, start timing, etc.\

The Time-Controlled Output Task 34 receives messages from the equipment task 34 when an output is needed for the part of the display screen that notifies the operator of connection, or when digits must be sent from the operator's desk. This task controls the time course of the digit outputs, and the periodicity of all flashing signals to be given to the operator.

Finally, we will look at Buf f er.-Storage-Task 35 which is an •'■■'[ expansion of Equipment and Diagnosis'-.Task 31. It is used to manage the storage of completed call registrations during \ periods, with fault in the common control unit or by.....a fault in the line leading to it.

Equipment Task 31 has a store assigned to each switching circuit on the operator's switching equipment, where information about the call is stored during the setup and execution of the call. At the end of a call or when the call load key is operated, the circuit store is made ready and the information in it is transferred to the buffer store. Under normal conditions, Kommunikationsr! , The task 30 is to immediately extract information from the buffer storage that responds to a call signal from the auxiliary processor at the common control equipment. ,

If no call signal is received, the information will remain in the buffer storage until it is full, and this condition is signaled to the operator, who can then empty the storage and prepare charge slips manually.<x>—

This entails reading out details of each call from the buffer storage to the display screen and preparing payment slips. Alternatively, data located in the buffer storage can remain there, as they are only read out when a call signal

.is received from the common control unit after the fault has been rectified. We will now describe the processor arrangement of the control equipment with reference to fig. 4, which shows the duplicate processor arrangement in more detail than in FIG. 1. The two processors 40, 41 are in fig. 4 referred to as the active processor and the standby processor. Each processor is a PDP11-34A, which is one of the members of the PDP11 family of processors made by Digital Equipment Corporation, and more specifically belongs to the middle class of this; the family. Each processor is provided with 64K words in a MOS memory, and has a floppy disk storage 42 with a capacity of 5 megabit groups,

a magnetic tape storage 43 for additional information, and a remote printer 44 for control and communication with a service engineer.

The processor is also equipped with one or more multiplexers 45, and in the system shown in fig. 1 there are four such, and these communicate with the lines to the operator desks via line drive circuits and receivers which are shown at block 46. The other processors 41 have similar equipment associated with them.

Each of the multiplexers such as 45 is a multiplexed interface for 8 or 16 asynchronous communication channels which, in the present system, operate in ASCII 8-level code at 2400 Band, over a suitable interface to the line driver circuits/receivers 46, which in turn communicate with the operator's desk. Each character received is parity checked by the multiplexer, which asserts a status bit when an error is detected, which status bit leads to a request to repeat the erroneous data. The receiving side of the multiplexer includes storage equipment where memory characters are stored, which eliminates the need to interrupt the processor each time a character is received. On the transmitter side, each channel is provided with a double storage of each character.

The line drive circuits/receivers in block 46 of both auxiliary processors are connected to the lines connecting the central control unit to the operator's desk, and the output controls of the backup processors. the sessor is set low so that the drive circuit outputs are in their high impedance state and can neither drive nor load into the channels. The setting of the output control units on the drive circuit for both processors occurs under the control of the inverter arrangement shown at 47.

The operation of the auxiliary processor, and this applies to both 40 and 41, can be summarized as follows: al Calling of the processors at the operator's desk on a regular basis

. and receiving messages sent from these processors when

they are called up.

b) Monitoring the response to the call from each operator desk processor and generating an associated output report, e.g. above *

the printer 44, when an operator desk does not answer the call f

c) Monitoring transmission errors on each line to the operator desk and generating an associated appropriate output in response

if a predetermined, fault-indicating threshold level is exceeded; d) Appropriate response to each type of message received from an operator desk processor, as described below. e) Response to operator or engineer command signals received over printer 44 to indicate functions such as setting an operator desk to directly connected or indirectly connected state, loading of upcoming programs, etc.

f) Response to monitoring command signals received over the printer 44 for such functions as opening and closing registers:-\

training the call load unit (in which the call records are stored), listing erroneous call records, etc.

During normal operation, the active processor stores call data, records in its disk or disk storage, and these call data.

is received from the operator desks. These registrations are stored by: using the Message Task which is part of the auxiliary processor. , software, in the part of the memory that is designated as storage# and from here the Load Task is read out which later provides.' .. r the load lists. The processor performs a validity check - •■•';' of each call registration received, and the relevant registration is only forwarded to the load list if it is known to be valid. If the load list is entered in a medium that has . a discrete capacity, can monitor commands via the printer, .44 . is introduced to stop operation while the medium, e.g. a disk or a coil is replaced. If the registration is not known to be valid, it will not be registered in this way, and a request for resending goes out to the relevant operator desk. Monitoring commands are also used to create a duplication ay et^ ' ■ ; ;j prior "volume" of the ppp payment list in the event that the medium ;

should be destroyed or if the output from the printer to: a)

records known to be valid, b) erroneous records, or c) all records from an identified nearby area of the coil storage. ......

As soon as one operator desk is brought to its directly connected one

in position, the auxiliary processor will at fixed hourly intervals send .out to this operator's desk as long as it is on the line, the date and time of day recorded by the system's clock.

In systems with options, such as e.g. validity via credit card routines or ordered calls, certain messages from an operator desk will require the addition, deletion or lookup of information in a database located on disk storage.

In the system described above, the control unit, which includes the auxiliary processor, is duplicated: We will now describe this arrangement with reference to figures 4 pg 5 and in particular the arrangement for switching from active to standby processor when this is necessary. Each processor is provided with a switch or selector 48, 49 which is called a double line selector, and over this the processor communicates with the other processor, with its own line's drive circuits and with the system alarm 50. The communication between the selectors 48, 49 and the corresponding processor takes place over one of the channels of the multiplexer such as 45.

Each processor, when powered on and the operating software package is loaded, either in its active state, is ready. :

condition, or .in a fault condition.

In the active state, the processor ensures that its line drive circuits 46 are activated, and issues calls on each line to the individual operator desk in sequence, and sends its output load records to disk and tape storage. It also makes calls to its dual line selector 48 with an active inquiry signal.

In addition, it sends out load registrations to disc-

or tape storage and, if the station allows deferred calls, it sends details of these to the standby process spring over an allocated multiplexer channel. in

The active state can occur automatically when the system is started, in which case the processor is set to the active state by the dual-line selector unless it receives an active signal from the other dual-line selector. Switching to the active state from the standby state can also occur at any at any time after the system is started, if the dual line selector no longer receives any activation signal from the other processor.

A processor leaves its active state as a result of a hardware or software failure such that the processor has entered an erroneous operating state, or when the dual-line selector has received an active signal from the other dual-line selector as a result of suppression of the switching selector or if basic dial- or tape failure causes the processor to no longer function.

In its standby mode, the ehprocessor will assume that its line drive circuits are not energized, and it will not call the lines to operator desks. Instead, it calls its dual line dialer with an emergency call, and if the system offers delayed call, it receives delayed call details from the active processor.

The standby state is entered automatically when the system starts

of the other processor, and the processor goes into standby mode

when its dual line selector receives an active signal from the other processor's dual line selector. It also enters the standby state from the active state when its dual-line selector receives an enable signal from the other selector as a result of suppression of the switching selector.

The standby state is exited by the hardware or * software re-exiting the faulty state, or by switching to the active state when its dual line selector detects that * an active signal is no longer being received from the other dual line selector.

A processor enters the faulty state when the processor itself fails or if a deep disk or tape failure occurs. When in this state, the processor will not call up the lines or the other double line selectors without this being otherwise acted upon due to the nature of the error. _._

The double line selector, one of which is shown in fig. 5. is• a.—1..: .~ electrical circuit unit which .has 8 ports as shown in fig. 5. Ports 1 and 2 are respectively input and output ports for the processor,

across the multiplexer, and ports 3 and 4 are the input and output ports of the second dual-line selector, and port 4 of each selector is connected to port 3 of the other. If the processor is active, the dual line selector will present a non-zero level on its port 4, which output signal is written from the state output unit 60. In the other states, which also include failure of the mains supply, it presents zero voltage.

Gate 5 is a drive output' from another state output unit 61, which supplies a non-zero voltage to enable its processor's drive circuits or zero voltage to enable it to be disabled. It also displays zero voltage when the power supply fails.

The port 6 is the fault alarm port which is directly connected to a latching input port of the alarm unit 50, fig. 4, and presents a voltage that deviates from zero when its dual line selector is energized, and is invoked by its processor during a predetermined time period. The presentation of zero voltage for 10 milliseconds or more energizes over a time circuit 62 the alarm input thus generating the alarm.

Port 7 is an active lamp output for the processor and the lamp

is preferably located on the front panel of the processor. This lamp lights up as soon as the processor is activated, and this is controlled by a zero voltage on the lamp alarm input. This port is

logically the same as ports 4 and 8.

The gate 8 is a turning gate for the alarm control, and two such gates are gate controlled as shown in fig. 4, 51, to the alarm unit 50. If, within 10 milliseconds, neither of these two ports has a voltage equal to zero at the input, the input to the unit' 50 will latch and the alarm will sound. This occurs during a switch due to an error in the active processor.

A dual line selector also includes a changeover switch 63,

which is a do-not-let-send work switch (make-before.e-break) operated by a non-locking push button on the front panel of. the processor. This switch has its input directly connected to port 3. If the button is not pressed, the output from switch 63 is directly connected to port 3 of the unit, so that it is at the same voltage. When the button is pressed, the output of the selector 63 is connected to the non-zero voltage across the state call block 64, and this causes its own processor to go from active to standby. This optionally switches the second processor from standby to .. active state, so that the second double-line selector leads ;. the voltage zero to input port No. 3. At this time the active lamp lights up until the second processor,<p>g button, can be released. It may be desirable to add damping. 250 milliseconds for release, thereby preventing improper or premature release.

Depressing or releasing button 63 in a standby processor will have no effect if the other processor is active. To preserve the non-zero voltage at the output of switch 63 when the second processor is active, the action of both pressing and releasing the button must be of the make before break type, with suitable protection circuits, between the tp double line selectors.

When a processor is in its active state or its standby state, it calls its dual-line selector every 50 milliseconds, and the call consists of a sequence of three characters, with different characters for active and standby processors. In the active case, the dual line selector will set or maintain the signals on ports 4, 7 and 8 so that they have a voltage deviating from zero, which indicates to port.3 to the second dual line selector and to the active lamp and to the alarm circuit that the processor is active . In the standby state, ■ the dual line selector will set or hold gate inputs 4, 7 and 8 at zero, indicating standby state.

In both active and standby mode calls, the dual line selector will provide either an indication to the processor on its outputs to port 2 that it should become or remain active, or an indication that it should become or remain in standby mode. Which of these two outputs is sent out depends on the last state of the selector 63, the latter state being indicated by a voltage deviating from zero, while the former state is indicated by a voltage equal to zero. The double line selector, and especially block 64 therein, also responds to any call to set or hold the output to port 6 at a value that deviates from zero.

If the dual-line dialer does not receive a call during a certain period, e.g. 100 milliseconds, it will assume that its processor has failed, and act as if it has received an emergency call. In addition to this, it sets the output on port 6 to zero to give an alarm and generates no energy on port 2. This no call state occurs immediately after start, and when the call starts, the operations will then occur as just described.\

The double line selector reacts to a voltage that deviates

from 0 on its port 3, from port 4 in the other double line selector, preventing the line driver circuits from operating their own processor. If port 3 carries a voltage equal to 0, the line drive circuits will be energized.

If the output of the selector 63 is zero voltage, the next output on port 2 will be the one indicating "active processor", while if there is a non-zero voltage, the next output on port 2 will be the one indicating "standby processor ". The alarm unit 50, fig. 4, is common to the two processors .40, 41, and is preferably energized by a reserve power source independent of the power supply to the processors. It has four inputs, two from the alternating alarm outputs of the two line selectors and two from the fault alarm outputs of the double line selectors. The first two of these are gate controlled by an OR gate. If, within .10 milliseconds or more, the alarm unit detects a zero voltage level on both of its first inputs or on the first and fourth inputs, it will energize its latched alarm circuits, which close two or more sets of relay outputs depending on the system's needs. The alarm circuits then remain energized until they are reset by actuation of a 'push button 52.

As indicated above, each processor will make calls to

its dual-line dialer every 50 milliseconds, where the first call sent out by the processor after it is switched on is an emergency call. Whether it has sent out an actiy-

or an emergency call, the processor will always respond to

the response it receives from the dual-line dialer to remain in or switch to the mode dictated by the dual-line dialer response, and the next call issued by the processor depends on the last dual-line dialer response. If the processor does not receive a response from the dual line dialer to the call within a predetermined time and period, it will generate a monitoring report. It continues to operate in its current state, but does not generate more repetitions of the current failure in the response. However, as soon as a response is again received by a call, a further monitoring report will be provided. The hardware of the control equipment is, in the same way as that which applies to the operator terminal, of a modular nature, as can be seen from fig. 6. Each of the blocks will now be discussed separately.

Communication Task 70 controls the transmission and reception of all messages to and from the operator desk processors. Splitting the communication handling into a separate Task means that the Main Message Task 71 can carry out "special transactions on

a simple series form. This Task 70 contains the following functions:

a) It receives outgoing messages from Meldings-O<p>pgave 71 and queues these in a chain. b) It transmits the outgoing messages as soon as the relevant lines become free. c) It waits for incoming approval of a message, and if it is not received in the correct time, it sends out the same message again

a fixed number of times.

d) . When a line becomes free and there are no outgoing lines. message which is queued for this, becomes each operator's desk as

are connected to this line, called up in turn.

e) It waits for a response to a call, and if there is an incoming message, it receives this message. f) If the message is correctly received, it is decoded------ -sent to Message Task 71. g) Error reports are sent to Report Task 72 via Message Task 71 as soon as a correct approval is not received within a reasonable time after a call, or if an outgoing message or an incoming message is not correctly received,

h) After a predetermined number of times an operator desk is considered indirectly connected or disconnected, and a report of

this is sent out to Report Task 72.

A special Operational Task (not shown in Fig. 6) is used for

to drive the lines to the operator's desk, and uses a multipurpose protocol, with a control status processor as the main station and up to 16 operator positions as slave stations. This Assignment is

responsible for generating, sending, receiving and checking headers, parity bits and check scans for each message.

Message Task 71 receives incoming messages from a

single input queue, processes these and then produces a response message as output before this runs through the sequences of instructions for handling the next incoming message. This Task performs system startup, loading and unloading of the panel's software, call authorization, formatting of load registration, as well as time stamping, and such selectable options as credit card authorization, ordered calls, etc.

Conditions for message processing that are open to change at each telephone station, such as e.g. call authorization and measurement of the load registration, are...separate subroutines that have well-defined program interfaces so that they can be easily replaced.-7 - Such rarely used functions as start and panel loading" ' are produced as overlying software so that Selectable instructions such as e.g. credit and authorization, pre-ordered calls,

can share the same memory.

Application of Message Task 71 that produces outputs other than those that go to the operator desk is left to other Tasks for processing via send/receive functions as follows

. that the Notification Assignment is not prepared for transmission. The charge registrations are sent from Meldings-Oppgave 71

to the spool storage 73 over the transmitter/receiver interface, and the Spool Task then writes the record to a circulating spool storage or to a disk. As soon as the Load Task 74 calls for a special load registration, Task 73 retrieves this from the disk (if necessary) and sends it out to the Load Task. It can also retrieve other load records

on demand for checking and keeping lists.

Load Task 74 creates the first load registers on magnetic tape 75 and opens or closes these registers in accordance with operator requests. As soon as the load register is open, Task 75 will call for the next record from Spool Gppgave 73, and as soon as this is satisfied,

it is attached in writing to tape, and the next registration is called for. As soon as a charge register is closed, a record of the register's sequence number, and the first and last record in the archive is maintained, and a report with this information is sent out. Charge Task 74 is also responsible for recording backup copies for the charge archive and for transferring special sequences of valid or invalid registrations to the tape for later analysis.

Report Task 72 controls the output from the reports produced by the other Tasks, which reports are received over the transmitter/receiver interface in coded form and then expanded into a form suitable for printing.

Command Task 76 controls the entry and transmission of command words from the printer 74. After translation, these command words are sent on to the relevant Task over the sender/receiver interface. Command words are provided for a) System startup and shutdown; b) Management and display of the status of each operator desk, ,

c) Loading programs for the operator desks.

d) Controlling the generation of error reports for the operator desks.

e) Management of the output from load registrations and exchange

of load bands.

f) Reading out selected sequences of valid and/or invalid load registrations to tape or printer. When the system is adapted, it starts itself and aligns itself in accordance with system data stored on disk 43, but it does not communicate with the operator consoles until it • is started by an operator or by a preset clock. The standby system can be in this monitoring or sleeping state and be ready to take over for the active system as soon as the lines are switched over. At least some of the opera dry desks may be equipped with automatic monitoring equipment to enable the entry of call details automatically.

Claims (6)

1. Recording equipment for call data for use in connection with a telecommunications center with at least one operator terminal, whereby call data regarding connections established with the help of an operator can be recorded, characterized in that the recording equipment works automatically during normal operation and includes a common command center where call data is recorded, that each operator terminal has a control desk for entering data regarding a connection to be set up, an individual processor controlled by a stored program, as well as interface circuits that give the operator terminal(s) access to a data line leading to the command center, where call data is to be recorded stored under the control of the terminal's processor, in a buffer storage at the operator terminal, where the command center also includes an additional processor controlled by a stored program, data recording equipment, as well as additional interface circuits that give the command center access to the operator terminal via data line n, where the command center calls the operator terminal (e) under the control of the additional processor and thereby searches for the operator terminals whose buffer storage contains information regarding a call whose data is to be stored, whereby one called operator terminal that has data about a call , s <y> are by sending this call data to the command center where this data is stored in the recording equipment under the control of the further processor, where further a called operator terminal which does not hold call data regarding a call to be recorded, issues a "No Call" message to the command center, and finally the command center, if it receives no message from a called operator terminal, interprets this as an error condition. 2. Registration equipment according to claim 1, characterized in that it comprises two or more data lines which all terminate at the command center, and where each serves several operator terminals. 3. Recording equipment according to claim 1 or 2, characterized in that the command center comprises two similar processors, each of which has its own data recording equipment and each of its own additional interface circuit, one of these processors with its associated equipment working in an active mode, while the other works in a standby mode, and where, if a fault develops in the active processor or its associated equipment, a switchover is made so that the active processor is switched to standby mode and the other processor is switched to active mode to take over control of the system. 4. Recording equipment according to claim 1, 2 or 3, and where an operator terminal is isolated from the rest of the equipment as a result of a fault condition, that this terminal can continue to function until its buffer storage is filled, at which time a visible indication is given to the operator » which can then record the calls manually. 5. Recording equipment according to claim 1, 2, 3 or 4, characterized in that the processors are controlled by software with a modular structure. 6. Registration equipment according to claim 1, 2, 3, 4 or 5, characterized in that at least some of the operator terminals are equipped with automatic line monitoring equipment, from which call data can be read and registered automatically*