JPS6046635A - Data highway device - Google Patents

Abstract

PURPOSE:To search double failures on a data highway rapidly by outputting a loop back command from a master station to a local station adjacent to the master station and sending transmission data to be sent to a signal line also to a loop back line. CONSTITUTION:When the signal line connected to the master station is disconnected, a loop back control part 5 regards a signal received from the local station through the loop back line as the received signal of the station concerned. A data receiving part in a data highway control part 8 detects that the received data are not transmitted from the master station, but are transmitted from the local station and writes control data indicating the existence of a fault in the control part 8. On the other hand, no signal is sent to the master station from the local station concerned and the control part 5 controls the local station so as to send the transmission data to the master station through the loop back line. A loop synchronization control part 7 in the master station outputs a loop back signal through command on the basis of the control data indicating the fault in the transmission data to form a loop by the loop back line.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data highway device, and in particular, a master station and a plurality of slave stations are connected in a loop within two transmission lines, a signal line and a loopback line, through which signals are sent in different directions. The present invention relates to a data highway device l arranged in a manner that transmits data between stations.

Conventionally, in this type of device, if one of the N (N22) stations making up the loop data transmission network fails, data transmission between all stations in the loop data transmission network may become impossible. Since this is expected, as a means to avoid this, the station in question automatically detects this failure and bypasses the station when a power failure occurs or a fatal error occurs at the station. It has become. In the case of an error that cannot be detected by the station itself, a means for manually bypassing the station is provided, thereby enabling data transmission between stations other than the station concerned.

In this method, if there is only one faulty station that cannot be automatically detected, it is a very effective method because it allows you to search for the faulty station by manually bypassing all slave stations one by one. If there are multiple slave stations, the above method will not be able to search for the faulty station, resulting in a system failure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data highway device that can quickly search for a failure even when a slave station has a double failure.

The data highway device according to the present invention is configured such that a master station sends a loopback command signal to any slave station, and when the slave station receives a loopback command signal directed to its own station, a transmission signal is transmitted to a signal line. It is characterized by being configured so that data can also be sent to the loopback line.

In other words, the master station sets the address of the slave station and the loopback command signal on the data frame for which it wants to cause a loopback so that it can be sent, and also prohibits data reception from its own signal line to prevent the loopback from occurring. The multiple slave stations constantly monitor the signals received from the signal line and detect that the loopback command signal is set and the address of their own station is set. Then, the transmission data sent to the signal section is forcibly sent to the loopback line as well. By doing this, a single loop is constructed.

Hereinafter, a data highway device according to the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of a data highway system according to the present invention, in which N stations are connected in a loop through two transmission lines, a signal line and a loopback line, through which signals are sent in different directions. This is for data transmission between N stations. Any one of these stations, for example, station #1, serves as a master station and intensively corrects delays occurring in the loop data transmission network and monitors the entire system. In Figure 1,
The counterclockwise line is the signal line, and the clockwise line 9 is the loopback line. Normally, the master station #l sends the same signal to both the loopback line and the signal line, and discards the received signal from the loopback line. . On the other hand, in each slave station #2 to #N, the received signal from the loopback line is only regenerated and relayed and transmitted to the lower station.

FIG. 2 is a frame configuration diagram of data flowing in the loop data transmission network of FIG. 1, where F is a frame synchronization section +
Dtd, 7 data section, LB C0NT B Control signal section that notifies loop banking, Address section that specifies the address of the slave station that you want to perform loopback on.
LBCMD is a loopback command unit for instructing the slave station to perform loopback, and Fe2 is a frame check sequence unit.

FIG. 3 is a block diagram showing the configuration of an embodiment of a station of a data highway device according to the present invention.

In the figure, 1 to 4 are signal converters, of which 1 and 4 convert transmission line signals from the transmission line into digital signals, and 2 and 3 are transmission units that send digital signals to the transmission line. This converts the signal into a road signal. 5 indicates a loopback control section. Reference numeral 6 denotes a timing extraction circuit, which extracts timing from received data. Reference numeral 7 indicates a loop synchronization control unit, which is a circuit included only in master station #1, and is used to intensively correct delays occurring in the loop data transmission network and monitor the entire system. It also inserts control data into the address section and loopback command section. Reference numeral 8 indicates a data highway control section, which is divided into two parts: a data receiving section and a data transmitting section. Among these, the data receiving section determines the presence or absence of frame synchronization and establishes or removes frame synchronization, and also checks Fe2 to detect whether it is good or bad. Then, the received data is imported only when all checks are normal. On the other hand, the data transmitter creates frame synchronization, creates Fe2, inserts data,
It inserts control data into the control signal section and sends out the transmission data. 9 indicates an interface unit with a terminal device (not shown).

Figure 4 shows the loopback control' in Figure 3, ylS5.
FIG. 2 is a circuit diagram showing the configuration of the circuit in detail. In the figure, 11
and 12 are circuits for detecting disconnection of the signal line reception signal sent from the signal converter 1 and the loopback line reception signal sent from the signal converter 4, respectively. Output °.

Reference numeral 20 denotes an OR circuit that takes the logical sum of the output from the disconnection detection circuit 11 and the three-station loopback command sent from the loop synchronization control section 7, and outputs a control signal. Reference numeral 14 denotes a first switch that switches between the signal line reception signal sent from the signal converter 1 and the loopback line reception signal sent from the signal converter 4 using a control signal from the OR circuit 20 and outputs reception data. It is a circuit. Reference numeral 13 denotes an OR circuit which calculates the logical sum of the output from the disconnection detection circuit 12 and the loopback reception command sent from the data/way control unit 8 and outputs a control signal. Reference numeral 15 denotes a second switching circuit that switches between the loopback line reception signal sent from the signal converter 4 and the transmission data sent from the data/way control section 8 in accordance with the control signal output from 13. 1
611'11: An exclusive NOR circuit that performs an exclusive NOR between the master station display sent from the loop synchronization control unit 7 and the loop check signal through command, and outputs a control signal. 1
A third switching circuit 7 switches between the transmission data sent from the data highway control section 8 and the output signal of the second switching circuit 15 using a control signal from the exclusive NOR circuit 16. An inverter circuit 18 outputs a control signal obtained by negating the control signal from the OR circuit 20. Reference numeral 19 denotes an AND circuit for controlling the loopback line transmission signal output from the third switching circuit in accordance with the control signal from the inverter circuit 18.

In FIG. 4, in master station #1, the master station display from loop synchronization control unit 7 is at logic level 1 pin, and each slave station #2 to #
N is set so that the master station display is at logic level I07. Further, in each slave station #2 to #N, the loopback signal through command is also set to the logic level @0'. In the master station #l, the loop synchronization control section 7 sends out a loopback signal through command based on the control data of the control signal section Li5CO, -NT in the received data. In other words, the loopback transmission command is normally at a logic level of 101, but when a signal sent from a higher-level station via a signal line is disconnected at a certain station, it is a control that constitutes data. Control data indicating a failure is placed on the signal unit LBCONT,
The loop synchronization control unit 7 detects this and sets the logic level to 11".
becomes. Therefore, in slave stations #2 to #N, since the control signal from the exclusive NOR circuit 16 is always at the logic level 11', the output signal of the second switching circuit 15 is transferred to the third switching circuit 17.
becomes the output signal. On the other hand, in master station #1, since the loopback/tsuku signal through command is at the logic level WOW during normal operation, the output signal of the third switching circuit 17 is transmission data.
When the loop synchronization control section 7 detects the control data, the control signal from the exclusive NOR circuit 16 becomes logic level '11' and the third switching circuit 17 passes the output signal of the second switching circuit 15 through it. Become.

Next, the operation of the embodiment of the present invention will be explained with reference to FIGS. 3 and 4.

First, normal operation will be explained. The transmission line signal sent via signal +1 from the upper station is received by the signal converter l, and the digital reception signal converted here is input to the loopback control section 5. Loopback control section 5
Since the control signal from the OR circuit 20 is at logic level 10', the first switching circuit 14 outputs the digital reception signal as its IT reception data. This received data is input to the timing extraction circuit 6 and is also input to the loop synchronization control section 7 only for the master station #1.

In the slave stations #2 to #N, this received data is directly input to the data highway control section 8. In the master station #1, the loop synchronization control section 7 uses the received data to correct delays occurring in the loop data transmission network and monitor the entire system, and then outputs the received data to the data highway control section 8. The data/eway control unit 8 performs frame synchronization playback from the received data to extract the data, passes this data to the interface unit 9, and adds a frame synchronization signal, etc. to the data passed from the interface unit 9. The transmission data is sent to the loopback control section 5. The loopback control unit 5 immediately sends this transmission data to the signal converter 3, and the signal converter 3 converts this transmission data into a transmission line signal and outputs this transmission line signal to the lower station via the signal line. do. Here, only in master station #1, the third switching circuit 17 outputs transmission data in response to a control signal from the exclusive NOR circuit 16, sends this transmission data to the signal converter 2 via the AND circuit 19, and sends the signal to the signal converter 2. The converter 2 converts this transmission data into a transmission line signal, and outputs this transmission line signal to the upper station via a loopback line.

On the other hand, a transmission line signal sent via a loopback line from a lower station is received by a signal converter 4, and the digital reception signal converted here is input to a loopback control section 5. In the case of slave stations #2 to #N, since the control signal from the OR circuit 13 is at the logic level log, the second switching circuit 15 outputs the above received signal, and the control signal from the exclusive NOR circuit 16 is at the logic level. Since there is '1w''c', the third
The switching circuit 17 outputs the reception signal sent from the second switching circuit 15, and the reception signal output from the third switching circuit 17 is sent to the signal converter 2 via the AND circuit 19.
is input. That is, in slave stations #2 to #N, the received signal output from the signal converter 4 is controlled by loopback control s5.
The signal is immediately input to the signal converter 2 via the signal converter 2.

This received signal is converted into a transmission line signal as a transmission signal by the signal converter 2, and this transmission line signal is output to the upper station via a loopback line. On the other hand, in the case of master station #1, since the control signal from the exclusive NOR circuit 16 is at logic level '0'', the received signal sent from the second switching circuit 15 is transmitted to the third switching circuit 17. That is, in the master station #1, the signal sent from the lower station via the loopback line is discarded by the loopback control unit 5.

Next, the operation when the signal received from the upper station via the signal source is interrupted will be explained. Such a disconnection occurs when the signal line between the upper station and the nuclear agent is disconnected. At this time, the disconnection detection circuit 11 operates in the loopback control unit 5 of the station and outputs the logic level WIW ft. The first switching circuit 14 converts the transmission line signal received from the lower station via the loopback line into a digital reception signal by the signal converter 4. On the other hand, the signal of logic level "1" outputted from the OR circuit 20 is converted to the logic level @01 by the inverter circuit 18, and is converted to the control signal of the CAND circuit 19.
stops the signal transmitted to the upper station via the signal converter 2 and the loop.

In addition, the data reception unit of the data/equie control unit 8 that receives the above-mentioned received data receives data from a state in which the received data is sent from the upper station via the signal line, and is sent via the loopback signal line of the lower station. When it detects that the state has changed to the normal state, control data indicating that there is a failure is placed in the control signal section LBCONT of the transmission data sent from the data transmission section.

On the other hand, in the upper station, since the signal is not sent from the lower station through the loopback line, the disconnection detection circuit 12 operates in the loopback control unit 5 and outputs a logic level of 11''. .

The second switching circuit 15 outputs the transmission data in response to the control signal of the logic level W and m sent from the disconnection detection circuit 12 via the OR circuit 13. The upper station is a slave station#
2 to #N, the control signal from the exclusive NOR circuit 16 is always at the logic level 11'', so the third switching circuit 17
outputs the transmission data output from the second switching circuit 15, and this transmission data is sent to the signal converter 2 via the AND circuit 19. The signal converter 2 converts the transmission data into a transmission line signal, and this transmission line signal is sent to the upper station of the upper station concerned via the loopback line. On the other hand, in the master station #1, the loop synchronization control unit 7 turns on the loopback signal through command based on the control data in the received data indicating that there is a failure in the control signal unit LBCONT, that is, the logic level is l.
l I, and the control signal from the exclusive NOR circuit 16 deviates from the logic level 111. Therefore, when master station #1 is the higher-level station, the master station converts the transmission data into a transmission line signal by the signal converter 2, and sends it to the higher-level station of the higher-level station (← master station) via the loop bank line. If master station #1 is not the upper station, the master station passes through the signal received from the lower station of the master station via the loop link line and loops it to the higher station of the master station. Send out via line.

As a result, one large data way loop is constructed using the loopback line from the upper station to the station, and the station receives the transmission data sent from the upper station via the loopback line. be able to.

When the above-mentioned disconnection is restored, the disconnection detection circuit 11 of the station concerned outputs a logic level of 10°, and the disconnection detection circuit 12 of the upper station of the concerned station outputs a logic level of 10°.
outputs the logic level 70', and the control data of the control signal section LBCONT constituting the data is restored to the information before it was cut off, thereby returning to the normal operation described above.

Next, the operation when a loopback command is issued from the master station to any slave station will be explained. The master station uses the loop control unit 7 to set "11" to the LBCMD section in the data format, and also sends the address of the slave station for which loopback is to be caused to the ADD section. A loopback command is issued, the switch is switched to the first switching circuit 14 via the OR circuit 20, and the data on the loopback line is used as received data.

The slave station, which has received the loopback command signal from the master station at the data highway control unit 8, issues a loopback control unit 5 loopback receive command, passes through the OR circuit 13, switches at the switching circuit 15, and sends it to the signal line. The data to be sent is also sent to the loopback line. In this way, a data highway loop is constructed using the signal line and the loopback line.

As is clear from the above explanation, by sequentially issuing loopback commands from the master station to the slave stations closest to the master station one by one, and gradually increasing the data highway looseness by one station, the data This has the advantage that when a double failure occurs on the highway, it is possible to quickly search for the failure.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of a data highway system according to the present invention, FIG. 2 is a frame configuration diagram of data flowing in the loop-shaped data transmission network of FIG. 1, and FIG. 3 is a diagram of a data highway device according to the present invention. FIG. 4 is a block diagram of one embodiment of the station, and is a circuit diagram of a specific example of the loopback control section in FIG. 3. Explanation of symbols of main parts 5... Loopback control section, 11.12...
... disconnection detection circuit, 13.20 ... OR circuit,
14,15.17...Switching circuit. Winding/Drawing? Figure J

Claims (1)

[Claims] A data highway in which one master station and multiple slave stations are arranged in a loop within two transmission lines, a signal line and a loopback line, through which signals are sent in different directions, and data is transmitted between the stations. In the apparatus, means for transmitting a loopback command signal from a master station to an arbitrary slave station, and transmitting data to be transmitted to the signal generator when the slave station receives the loopback command signal to the loopback line. What is claimed is: 1. A datano-iway device characterized in that it is configured to include means for sending out data.