JPS6162960A - Device scroll apparatus - Google Patents

Abstract

PURPOSE:To detect easily the erroneous insertion of plug-in by providing a selecting circuit which an errorneous insersion signal line, a gate circuit, and a selection impossiblility signal line. CONSTITUTION:A selecting circuit 25 is provided with an erroneous insetion signal line 19, a gate circuit 48, and a selection impossiblity signal; line 18. In case of erroneous insertion, the erroneous insertion signal line 19 is grounded through a mother board 35, and the selection impossbility signal line 28 is made active by the gate circiuit, and a control TAGBUS signal 13 and a selection holding signal 12 are gated by a receiver circuit 42. Thus, the selecting operation is impossible, and DISABLE is displayed on an ENABLE/DISABLE display device by the selection impossiblity signal line 18.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a device cross call device, and in particular, a device cross call device suitable for malfunctions caused when a plug-in equipped with an interface circuit between a control device and a drive device is mistakenly inserted. Regarding equipment.

[Background of the invention]

Figures 1 to 5 below describe problems caused by incorrect insertion of a plug-in equipped with an interface circuit between a control device (for example, a magnetic disk control device) and a drive device (for example, a magnetic disk device) in conventional device cross-call devices.
This will be explained using figures.

FIG. 1 shows a block diagram of a device cross-call device. This device includes a control circuit 11 and a control circuit 21.
The drive circuit 51 can be controlled via the selection circuit 15 and the selection circuit 25 from two paths. In the case of a single call configuration, the control circuit 21 and the selection circuit 25 cannot be installed (hereinafter, the path of the control circuit 11 is called the A system, and the path of the control circuit 21σ is called the B system) ENABLE /
DISABLE switches/indicators 17 and 27 are used to enable/disable selection of each system.

The selection of the drive circuit 51 will be explained using FIGS. 2 and 5. FIG. 2 is a diagram showing selection circuits 15 and 25.

In the case of selecting the A system (path of the control device 11), the control circuit 11 connects the selection hold signal line 12 and the control TAG1.
is output to the selection circuit 15 via the 3AS signal line 15.

In the selection circuit 15, this signal is received by the receiver circuit 42, and TAGB is output only when the E#IBLE signal line 16 is active.
(Sends the JS signal to the machine number comparison circuit 45.
5, the machine number signal line 55 from the drive circuit 51 and TAGB
A comparison is made with the machine number to be selected on the US signal, and if a match is found, the machine number match signal line 47 is activated. At this time, if the selection time division signal line 24 and the selection response signal 28 from the selection circuit 25 are active and the latch circuit 4
5 is set as the selection response signal.

Line 14 becomes active to complete the selection operation.

After that, the control circuit 11 outputs the selection response signal line 14 to A.

After confirming that the signal has been activated, various commands are output on the control rAGBUs signal line 15, and the selection circuit 1
5, the signal is sent to the driver circuit 44 via the receiver circuit 42. If the selection response signal line 14 is active, the driver circuit 44 causes the drive circuit 51 to drive i'AGBU.
A command is output via the s signal line 52 to drive.

For the case of a) selection σ) from system B, proceed in the same manner as for system A. However, when the A system is in the selection state in a cross-call configuration, even if a selection command is output from the control circuit 21 in the B system, the selection response signal line 14 is active in the selection circuit 25, so the latch is not activated. The circuit 45 is
) and no selection is made. However, as shown in FIG.
A system) and fCB system) rise at the same time, the selection response signal e (/I
system) and t (B system) cannot be inhibited. In order to prevent this, the oscillator signal α is input 17 to the time division circuit 46 of the selection circuit 25, and the time division signals S and CF are alternately outputted. This time-division signal is sent to the selection circuit 15 and gates the set signal of the Lavchi circuit 45. Also, time-sharing Shingetsu C is A
The signal of the latch circuit 45 is gated through the system/B system switch. Therefore, even if the selection hold signals 'r4a and f rise simultaneously in FIG. 5, the selection response signals e and 9 are not set until the time division signal rises. When the time division signal 6 rises, the selection response signal 6
Get throated. Next, even when the time division signal C rises, the selection response signal 9 is not set because the selection response signal e is set. When the selection holding signal d falls and the selection response signal f is reset, the selection response signal t can be set.

However, if the selection circuit 15 and the selection circuit 25 are inserted by mistake, the settings of the A system/B system switch will be different, and the oscillator signal line S4 will not be input to the A system. The divided signal is always active, and since the time division code line 28 is not input in system B, it is pulled up and always active, and the same drive circuit is selected from two systems at the same time, resulting in data destruction or system down. This leads to serious failures such as the following, and the problem is that self-diagnosis is not enough to point out incorrect insertion.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the problems of the prior art described above, and to provide a device cross-call device that can detect erroneous insertion of a plug-in.

[Summary of the invention]

In order to reduce costs, it has become common to use the same board, make some changes, and use it for other purposes.
If such boards are inserted incorrectly, detection by a simple test program will become unclear. Therefore, there is a risk that incorrect insertion may lead to circuit malfunction, leading to serious trouble.

However, this problem can be easily solved by using both the platter and the motherboard.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described using FIG. 4.

The feature of this embodiment is that the selection circuit 25 includes an erroneous insertion signal line 19;
This is because the gate circuit 4B and the non-selectable signal line 18 are provided.

In other words, if an incorrect insertion is made as shown in Figure 4, selection is always possible from system B, but in system A,
The incorrectly inserted signal line 19 is the motherboard.

Since it is grounded via the gate circuit 48, the unselectable signal line 18 is activated and the receiver circuit 42 is grounded via the gate circuit 48.
The control TAGBUS signal 15 and the selection hold signal 12 are gated. This pressure disables the selection operation from the A system, and the selection disable signal line 18 causes the ENABLE/
Dis, 4BLE display I) ISABLF.

Display.

Therefore, according to this embodiment, it is possible to prevent failures due to erroneous plug-in insertion, and at the same time, to facilitate the detection method when erroneous insertion occurs.

〔Effect of the invention〕

According to the present invention, a method for detecting erroneous insertion of a similar plug-in has become easier. Even if the display is overlooked, it is effective in preventing malfunctions.

Furthermore, according to the present invention, even if additional wiring is required on the motherboard, it is only necessary to add circuitry to one plug-in system, which is economically advantageous.

・　7　・

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a drive cross call device. FIG. 2 is a block diagram of a conventional selection circuit, and FIG. 5 is a block diagram of a conventional selection circuit.
FIG. 2 is a waveform diagram provided for explanation. FIG. 4 is a block diagram of a selection circuit of a drive scroll device that detects erroneous plug-in insertion and prevents malfunction according to the present invention.

Claims (1)

[Claims] A plurality of drive devices are controlled by two control devices via different routes, and a first plug-in inserted into a first selection circuit and a second plug-in inserted into a second selection circuit are controlled. In the device cross-call device comprising a plug-in, the second plug-in has a signal line that shorts at least two terminals, and the first selection circuit has a signal line that shorts at least two terminals, and the first selection circuit
A device scrolling device characterized in that the device scrolling device is configured such that only the second plug-in operates when the second plug-in is inserted.