JPH0454519Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application This invention relates to a terminal switching device for appropriately switching and connecting a large number of terminal devices to channels of different computer systems.

B. Summary of the invention The terminal switching device of this invention has multiple channels of contact type switching relays for connecting a port connected to a terminal device to one of two ports each connected to a channel of a different computer system. Each relay is configured to switch individually according to the switching signal stored in the register, and the condition is that the address input from the control line matches the set address, and the switching signal of the register is set according to the input from the control line. is rewritten, and a switching signal for the register is sent to the control line.

C. PRIOR ART When constructing a system in which a plurality of computer systems are organically linked, operational and economic constraints may require the same terminal device to be selectively connected to channels of different computer systems.

Conventionally, in such cases, two channels and one
A switching circuit was connected between the two terminal devices, and an interface for control (including monitoring) was attached to this switching circuit.

D. Problems that the invention aims to solve If there is only one terminal device or a very small number of terminal devices to be switched and connected to channels of different systems, the conventional method of providing a switching circuit and a control interface for each terminal does not pose much of a problem. do not have. However, as the number of terminal devices to be switched and connected increases, the number of control interfaces becomes too large with conventional individual support, which creates major restrictions in terms of the number of signal lines, number of terminals, and control procedures. This makes it impossible to build a rational system.

This idea was devised in view of the conventional problems mentioned above, and its purpose was to provide a collective switching device for use when there are a large number of terminal devices to be switched and connected to different channels. To provide a terminal switching device having a very simple overall configuration, in which switching control of each channel and monitoring of the switching state can be performed by a simple interface using a party line.

E. Means for solving the problem The terminal switching device according to this invention switches the connection of each terminal device to the channel of each computer system in a system including two different computer systems that share a plurality of terminal devices. A plurality of devices are provided corresponding to each terminal device.
A contact type switching relay that connects the terminal device side port to one of the two computer system side ports, a register for storing the switching signal corresponding to each contact type switching relay, and a register for storing the switching signal corresponding to each contact type switching relay. A drive circuit that operates each of the switching relays according to each switching signal, an address setting device for setting the unique address of the device, and a match between the address signal input from the control line and the address of the setting device. Under the condition that the switching signal input from the control line is stored in the register, the control line interface is configured to send the switching signal stored in the register to the control line.

F Effect Generally, when different computer systems share a terminal device, the computer systems are connected by a link device, and predetermined information is exchanged between the computer systems, thereby controlling connection and disconnection of the terminal devices.

According to the terminal switching device according to this invention, when switching between multiple terminal devices, a so-called party line method is adopted, a single control line interface is provided to control the drive circuit from the computer system, and multiple terminal devices are switched. The switching signals of all terminal devices are handled collectively. That is, an N-bit switching signal indicating switching of N terminal devices is transmitted and received between the computer system and the control line interface. The switching signal received at the control line interface is written into an N-bit register, and the drive circuit operates the switching relay according to the contents of this register. Conversely, the contents of this register are sent to the computer system as a monitoring signal. Furthermore, since a contact relay is used as a changeover switch, there are extremely few restrictions on electrical coupling, and various terminal devices can be connected. The switching relays of each channel are collectively controlled by a register switching signal, and the contents of this register can be collectively rewritten by a signal from a common control line, and are collectively sent to the control line. Can be monitored.

G. Embodiment The figure shows the configuration of a terminal switching device according to an embodiment of this invention. In this embodiment, switching functions for eight channels are mounted on one printed circuit board.

11 to 18 are contact type switching relays for 8 channels, each of which connects port C _i to either port A _i or B _i (i = 1, 2,
3,...8). A terminal device T _i is connected to each port C _i , and each port A _i is a channel CHi of computer A.
Each port B _i is connected to a channel CHj of computer B (j=i+8).

The number of signal lines in one channel is, for example, 10, and each relay 11 to 18 is a 10-circuit mechanical voltage-free contact that switches 10 signal lines.

8 bits corresponding to each of the 8 relays 11 to 18
Switching signals for each of the relays 11 to 18 are set in the bit register 3. Drive circuit 2 is register 3
Each relay 11
-18 are switched and controlled. In the illustrated example, the arrangement order of the relays 11 to 18 corresponds to the arrangement order of the 8 bits of the register 3, and the relay corresponding to the bit to which the switching signal "1" is set is switched to the A side, and the relay is switched to the A side. The relay corresponding to the bit to which the signal "0" is set is switched to the B side.

6 is a control line that is a party line; 4 is a control line interface that connects this control line with the device; and 5 is an address setter for setting a unique address of the device. This setting device 5 is preset with an address for distinguishing the present device from other devices connected to the control line 6 (devices having the same configuration as the present device, etc.). The 8-bit data in the register 3 can be freely written/read by the control line interface 3.

When switching one or all of the relays 11 to 18, the control device (computer A or B or other device) uses the set address signal, the 8-bit switching signal to be written in the register 3, and the signal write A control signal indicative of an operation and a signal arranged in a predetermined format are connected to the control line 6.
Output to. The control line interface 4 receives this signal and writes the received 8-bit switching signal into the register 3 only when the input address and the set address match. Then, the drive circuit 2 switches each relay 11 to 11 according to the updated switching signal.
18 are switched.

When the switching connection state of each relay 11 to 18 is to be monitored by the control device, the control device outputs to the control line 6 a signal in which the address signal and a control signal indicating a monitor command are arranged in a predetermined format. Control line interface 4 receives this, and if the addresses match, interface 4 reads an 8-bit switching signal from register 3 and outputs it to control line 6. The control device receives this.

By the way, the above embodiment is a collection of 8 channels, but relays 11 to 18, drive circuit 2, and register 3 for 8 channels are further added (a board on which these are mounted is added), and the control By sharing the line interface 4 and address setter 5, it becomes a switching device for 16 channels. In this way, adding channels is very easy.

Further, depending on the number of signal lines required by the terminal device, for example, ports C1 and C2 can be assigned to one terminal device. In this way, it can be used in a very versatile and flexible manner.

H. Effects of the invention As explained in detail above, the terminal switching device according to the invention has a configuration in which contact type switching relays for multiple channels are slidably mounted and these are controlled via a common control line interface. Therefore, even if the number of channels is large, the circuit configuration of the control line interface can be small, and the number of write/read control lines can be small, making it possible to simplify and downsize the overall device configuration. Moreover, it has the advantage that even if a terminal device is added, it can be handled without adding a control line. Furthermore, since a contact relay is used as the changeover switch, there are no restrictions on the terminal device that can be changed over, making it extremely versatile.

[Brief explanation of the drawing]

The figure is a block diagram of a terminal switching device according to an embodiment of this invention. 11-12... Switching relay, T1-T8... Terminal device, CH1-CH8... Channel of computer A, CH9-CH16... Channel of computer B.

Claims (1)

[Scope of utility model registration request] A device for switching the connection of each terminal device to a channel of each computer system in a system equipped with two different computer systems that share a plurality of terminal devices, which device is provided in plurality corresponding to each terminal device and has two computer systems. A contact type switching relay that connects the terminal device side port to either one of the grid side ports, a register for storing the switching signal corresponding to each contact type switching relay, and each memory stored in this register. a drive circuit that operates each of the switching relays according to the switching signal;
An address setter for setting the unique address of the device, and on the condition that the address signal input from the control line matches the address of the setter,
A terminal switching device comprising: a control line interface for storing a switching signal input from the control line in the register, and transmitting the switching signal stored in the register to the control line.