JPH02114728A - Signal cable connection test circuit - Google Patents

Abstract

PURPOSE:To surely point out misconnection or unconnected parts by using one of core wires of each signal cable as a signal line for receiving and transmitting a test signal, sending a pulse from one device to this signal line and counting the pulse at the opposite device. CONSTITUTION:A flip-flop circuit 4-1 is set only once. The output signal 1 reaches a counter 5-1 and the count of the counter reaches 1. Moreover, the said circuit 4-2 is reset after it is set once, and then set again. Thus, two pulses are outputted and reach a counter 5-2 and the content reaches 2. A counter outputted from flip-flop circuit 4-1-4-n is counted by corresponding counters 5-1-5-n respectively. Thus, whether or not a signal cable is connected correctly is easily identified by comparing the counts of the counters.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a circuit for testing the connection status of signal cables that connect devices, and aims to detect incorrect connections of signal cables between devices at an early stage. A circuit that sends a test pole to at least one of the core wires of each signal cable, and a different number of circuits for each of the above circuits corresponding to different cables. and counting the pulses on the core wire of each cable to which a circuit for sending the pulses to the other device is connected to the other device of the devices connected by the signal cable. It is constructed by providing a counter and means for reading and outputting the value of the counter.

[Industrial Field of Application] The present invention is applicable to signal cables when a system is configured by connecting devices with signal cables, such as a main body device and an input/output control device in an information processing device. It is related to a circuit for testing whether or not the signal cable is installed correctly between the intended devices, and in particular, whether there is an error in the installation of the signal cable and which device the signal cable is installed incorrectly. This relates to a signal cable connection test circuit that is capable of detecting.

[Prior Art] FIG. 3 is a diagram showing an example of the configuration of an information processing system, in which 51.52 is a central processing unit (CPU), 53 is a memory, 54.55 is a channel control device (CHC), and 56 ~5
Reference numerals 9 represent channel devices, 60 to 63 represent input/output control devices, and 64-1 to 64-n and 65-1 to 65-n represent input/output devices, respectively.

As shown in the figure, each device is connected by a signal cable 66.

In the same figure, these signal cables are connected between devices as if
Although it is depicted as being connected with a cable in the book, this only represents the connection relationship between devices; in reality,
There are many cables for data transfer and control signals, and there are also cables for monitoring and alarm signals, so a single device requires multiple cables. is connected.

Usually, these cables have a connector at the end, and connection with a device is achieved by coupling the connector.

[Problems to be Solved by the Invention] When operating an information processing system with the system configuration described above, when a failure occurs, it is necessary to temporarily change the connections between devices in order to search for the failure location, or to identify the failure location. When a device or connection path fails and cannot be used, the system is reconfigured by changing connections until the repair is completed.

As mentioned above, there are multiple signal cables connected to one device, and devices of the same type are usually installed closely together, and connectors and the like are also of the same standard. Reconnecting signal cables must be done very carefully to avoid connection errors.

Particularly when changing device connections while the system is running, a connection error may cause serious consequences such as destruction of file contents or system stoppage.

Therefore, as a verification method to prevent human errors related to signal cable connections, conventionally,
A method of testing by transmitting and receiving different fixed patterns has been considered.

However, with this method, when the number of signal cables increases,
This requires a large number of core wires for the identification pattern, which reduces the efficiency of using the core wires of the signal cable, so it has rarely been used in practice.

In view of these conventional problems, the present invention provides a means for testing whether a signal cable is correctly connected to a predetermined device without requiring many core wires of the signal cable. is intended to provide.

[Means for Solving the Problems] According to the present invention, the above objects are achieved by the means described in the claims. That is, the present invention is a circuit for testing whether or not a plurality of signal cables connecting devices are correctly connected. A circuit for sending test pulses to at least one of the core wires of the cable, a means for applying a different number of pulses to each of the circuits corresponding to different cables, and a device that can be connected with the signal cable. A signal cable in which the other device is provided with a counter that counts the pulses on the core wire of each cable to which the circuit for sending out the pulses to the other device is connected, and a means for reading and outputting the value of the counter. This is a connection test circuit.

[Function] In the signal cable connection test circuit of the present invention, at least one of the core wires of each signal cable is used as a signal line for transmitting and receiving test signals.

Then, one device connected to the corresponding cable sends pulses to the signal line, and the pulses are counted by the other device.

At this time, if the number of pulses sent out is different for each device and the number of pulses sent out from one device is compared with the value counted on the receiving side, each device can be correctly connected as desired. You can easily know whether the

To send out test pulses, for example, if the device in question has a scan-in/scan-out function, connect the output side of a specific flip-flop circuit to the test core wire of the signal cable to activate the scan-in function. It is also possible to perform this by setting/resetting the flip-flop circuit a necessary number of times.

Furthermore, the count value of the counter on the receiving side can also be read by using the scan-out function.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention,
1 is device Δ, 2-1 to 2-n are devices B and 3-1, respectively.
-3-n are signal cables, 4-1 to 4-n are flip-flop circuits for sending out test pulses, 5-1 to 5-n are counters for counting received test pulses, and 6 and 7 are signal cables. Represents a connector for connection.

In FIG. 1, flip-flop circuit 4-1 is sent only once. This output signal (P1°) reaches the counter 5-1 via the connector 6, the signal cable 3-1, and the connector 7, and the count value of the counter becomes "1".

Further, the flip-flop circuit 4-2 is set - degree, then reset, and then set again. As a result, two pulses are output, which reach the counter 5-2 via the connector 6, the signal cable 3-2, and the connector 7, and the value of the counter 5-2 becomes "2".

In this way, each flip-flop circuit 4-1 to 4-
n are each controlled to output a different number of pulses by repeating set/reset.

Since the pulses output from each flip-flop circuit 4-1 to 4-n are counted by the corresponding counters 5-1 to 5-n, the flip-flop circuits 4-1 to 4-n
Number of pulses output from 4-n and counters 5-1 to 5
The count value of -n is the same value for each corresponding set.

Therefore, by comparing these, it is possible to easily identify whether the signal cable is correctly connected.

For example, in the configuration shown in FIG. 1, the flip-flop circuit 4-3 outputs three pulses, and the flip-flop circuit 4-4 outputs four pulses, so the value of the counter 5-3 is The value of the counter 5-4 should be “4n”, but the value of the counter 5-3 is “4n”.
'', and if the value of counter 5-4 is "3", then
As shown in FIG. 2, incorrect connections can be immediately identified.

Further, for example, in the configuration of FIG. 1, the counter 5-1
If any value among .about.5-n is 0'', it can be seen that the signal cable corresponding to the corresponding counter is not connected.

Flip-flop 4 for sending out the required number of pulses
Setting/resetting of -1 to 4-n can be easily controlled using the scan-in/scan-out function. That is, this can be easily realized by moving, as scan-in data, data of a pattern capable of outputting the required number of pulses through a scan-in operation.

The values of each counter may also be read using the scan-out function.

The number of digits in the counter is when the total number of cables is N (lo
g2N+1) bits are required.

If the device does not have a scan-in/scan-out function, a circuit is required to set/reset the flip-flop circuit the required number of times and read the counter value, but these are extremely small. This can be achieved by adding hardware.

If these systems are equipped with a service processor, a system that can be tested very easily can be constructed by relying on the service processor for processing.

In the above description, the case where the devices exist separately and the signal cables are used to connect them is described, but in the present invention, a plurality of units exist in one device,
Of course, it can also be applied as a means for preventing or detecting erroneous connections of signal cables connecting the respective units.

[Effects of the Invention] As explained above, according to the method of the present invention, it is possible to easily detect a misconnection or disconnection of a signal cable between devices, and it is possible to detect the misconnection or disconnection of a signal cable between devices. This has the advantage of being able to reliably point out the points.

In addition, the transmission and reception of signals for testing is performed using one of the core wires of the cable.
It is sufficient to configure the transmitting side circuit so that the test signal can be generated in the main signal, and it is also possible to use it in combination with a general signal, without deteriorating the utilization efficiency of the cable core.

The circuit of the present invention can be realized with an extremely small amount of hardware, and by providing a test circuit independently, tests can be performed without affecting normal operation signals. Another advantage is that tests can be performed from a service processor or the like without stopping system operation.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram illustrating detection of erroneous connections, and FIG. 3 is a diagram illustrating an example of the configuration of an information processing system. .

Claims (1)

[Claims] A circuit for testing whether or not a plurality of signal cables connecting devices are connected correctly, the circuit comprising: transmitting each signal to one of the devices connected by the signal cables; A device that is provided with a circuit that sends test pulses to at least one of the core wires of the cable, and a means for applying a different number of pulses to each of the circuits that correspond to different cables, and which is connected by a signal cable. The other device is provided with a counter that counts the pulses on the core wire of each cable to which the circuit for sending the pulses to the other device is connected, and means for reading and outputting the value of the counter. A signal cable connection test circuit featuring: