JPH09128112A - Process operator's console - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically separate or connect the SCSI bus terminator of an SCSI bus by providing a means detecting the connection situation of the hard disk of a POC control part and an external SCSI bus equipment. SOLUTION: An external connector 13 provided at one terminal of the SCSI bus 12 connecting the hard disk interface 10 of MPU 1 and a hard disk 11 is connected with an external SCSI bus corresponding equipment such as a cassette magnetic tape equipment 16 by an external signal cable 15. A signal cable presence/absence detection means detects the presence of the connection of the external signal cable 15 and separates the SCSI bus terminator of the external signal connector part from the SCSI bus 12, thereby extending the SCSI bus 12 to the external SCSI corresponding equipment, and connecting MPU 1 the hard disk 11 to the external SCSI corresponding equipment such as the cassette magnetic tape equipment 16. Then POC is normally operated, the external signal cable 15 is not connected.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a process operator's console.

[0002]

2. Description of the Related Art A POC for a process control system is a CR
On the T, an instrument screen image of an industrial instrument, a graphic screen showing the system diagram of the plant, a trend screen showing the progress of the control state, etc. are displayed to perform control operation and monitoring by keyboard operation. On the other hand, the control unit of the POC is connected to the process control controller distributed by a dedicated communication network, and the operating status and control contents of the plant are displayed on various CRT screens via the process control controller, and the display contents are displayed by keyboard operation. Make changes and control operations. At this time, the operation program of the POC and various CRT display data, the control data of the process control controller, the process data indicating the operation status of the plant, etc. are stored and held in the hard disk in the POC.
Further, as a means for maintaining the data in the hard disk, a POC controller is generally equipped with a floppy disk device and a cassette magnetic tape device, etc., and a floppy disk is suitable for copying and rewriting a part of the data in the hard disk. Since the magnetic tape cassette is suitable for copying and rewriting the entire contents of the hard disk, it is used depending on the application.

[0003]

As described above, the POC is used.
Is a POC control program in the hard disk,
Various CRT display data, process control controller control information, process data indicating plant operation status, etc.
The control information of the entire process control system is stored. In recent years, in the process control system industry, there are significant movements toward downsizing and price reduction of products, and the maintenance equipment that has been equipped as standard with the minimum hardware is treated as an option. It is desirable to use it as a so-called tool that is installed only during maintenance.

On the other hand, as a means for externally inputting or outputting a program or data to the hard disk of the POC, it is necessary to copy and store the operating conditions and results of the plant in an external storage medium even under normal operating conditions. A disk device is equipped as standard, but the storage capacity of the media of the Proppy disk is about 1 megabyte, while the storage capacity of the hard disk is several tens of megabytes to several hundreds of megabytes, and all contents can be written or written. When reading out, tens to hundreds of floppy disks are required, and a lot of time is required for the work, so system startup time and maintenance time are problems. According to the present invention, the POC controller is provided with an external signal connector for connecting an external SCSI bus device such as a cassette magnetic tape device capable of handling data transfer with a hard disk at high speed and with a large capacity. It is provided with a means for detecting, and automatically disconnects and connects the SCSI bus terminator of the SCSI bus according to the detection result.

[0005]

According to the present invention, an external SCSI is provided at one end of a SCSI bus connecting a hard disk interface of an MPU and a hard disk to a control unit of a POC.
A bus connector signal connector and a SCSI bus terminator are provided, and a signal cable connection presence / absence detection unit that is connected to an external SCSI bus compatible device is also provided, and the SCSI bus terminator is automatically disconnected and connected according to the signal cable connection presence / absence detection result. Then, when there is no signal cable connection, S
Connect the CSI bus terminator and disconnect the SCSI bus terminator when connecting the signal cable to perform SCSI operation.
This can be achieved by connecting a cable that supports an external SCSI bus with a bus terminator.

That is, the S that connects the hard disk interface of the MPU in the POC controller and the hard disk
The external signal connector provided at one end of the CSI bus is used to connect an external SCSI bus compatible device such as a cassette magnetic tape device with an external signal cable during maintenance. The signal cable presence / absence detection unit detects the presence of the external signal cable. By disconnecting the SCSI bus terminator of the external signal connector from the SCSI bus, the SCSI bus can be extended to a device compatible with the external SCSI bus, and the MPU can support external SCSI bus devices such as hard disks and cassette magnetic tape devices via the SCSI bus. Is connected and all the data in the hard disk can be copied or rewritten. On the other hand, in the normal operating state of the POC, nothing is connected to the external signal connector, and the signal cable presence / absence detecting means detects the absence of the external signal cable, and the SCSI bus terminator of the external signal connector is detected.
When the MPU is connected to the SCSI bus, the MPU can read and write the program or data to the hard disk via the SCSI bus.

[0007]

DETAILED DESCRIPTION OF THE INVENTION A process operator's console according to the present invention will be described below with reference to FIGS. First, a block diagram of this embodiment is shown in FIG.
In this embodiment, an MPU 1 and an MPU bus 2 extended from the MPU 1, a memory 3 for storing programs and data that control the operation of the POC, a communication interface 4 for communicatively connecting with a process controller, drawing of various display screens, and operation input. CRT interface 5 to perform and CRT to display on screen
A display 6, a keyboard 7 for key input, and a floppy disk interface 8 for copying or rewriting data on a part of a hard disk using an external storage medium.
A floppy disk drive device 9 and a hard disk interface 10 that connects to a hard disk via a SCSI bus 12, a hard disk 11 that stores and holds various programs and data, and an external signal connector section 13 that externally connects the SCSI bus 12 and a power source inside the POC are commercially available. It is composed of an AC / DC power supply 14 made from a power supply, and an external signal cable 15 and a cassette magnetic tape device 16 are externally connected to the external signal connector portion 13 when maintaining all data in the hard disk 11. Here, in addition to the connector for connecting the external signal cable 15, the external signal cable presence / absence detecting means, the SCSI bus terminator and the SCSI bus terminator are separated and the connecting means is built in the external signal connector section 13.

Next, the SCSI bus operation of the POC during maintenance and normal operation will be described with reference to FIGS. In FIG. 2, the external signal cable 1 is connected to the POC controller 17.
5 and the cassette magnetic tape device 16 are connected, and only one of the 18 SCSI bus signal lines is shown as a signal line. The SCSI bus requires impedance matching in which both ends of the physical bus are respectively connected by two resistors. In this embodiment, one end of the SCSI bus is used as the hard disk interface 10 and R1 is pulled up to + 5V and R2 is pulled down to 0V, and the middle point is set. As a signal line,
Further, D1 to be transmitted to the signal line is connected to R1 to be received, next, the hard disk 11 is connected on the extracted SCSI bus, D2 to be transmitted to the signal line is connected to R2 to be received, and then the external signal connector unit 13 is connected. A cassette magnetic tape device 1 in which the external signal cable 15 and the cassette magnetic tape device 16 are connected from an external signal connector 18.
In R6, impedance matching of the SCSI bus is performed by R5 and R6, and D3 that transmits to the signal line and R3 that receives are connected. At this time, the external signal cable connection presence / absence detection circuit 19 in the external signal connector unit 13 is R7. By +
The input pulled up to 5V is connected to 0V in the cassette magnetic tape device 16 via the external signal cable 15 and becomes a low level. Therefore, the output of the external signal cable presence / absence detection circuit 19 becomes a high level and the SCSI bus terminator 20 is connected. The connection circuit is switched off and the resistances of R3 and R4 are disconnected from the SCSI bus. As a result, the SCSI bus is bus matched by R1 and R2 at one end and R5 and R6 at the other end. Then, the hard disk interface 10, the hard disk 11, and the cassette magnetic disk device 16 are connected to the SCSI bus by one external signal cable.

FIG. 3 shows a normal process operation state in which the external signal cable is not connected. In FIG. 3, the hard disk interface 10 and the hard disk 11 perform the same operation as in FIG. 2 in the external signal connector section 13. The external signal cable presence / absence detection circuit 19 becomes high level because the input signal from the external signal connector 18 is only + 5V pull-up by R7. As a result, the output of the presence / absence detection circuit of the external signal cable 19 becomes low level S
The CSI bus terminator 20 is disconnected, the switch of the connection circuit is turned on, and R3 and R4 are switched to S via the switch.
The operation is to perform bus matching at one end of the CSI bus.

Next, referring to FIGS. 4 and 5, P according to the present embodiment will be described.
An example of implementation in OC is shown. FIG. 4 is a top cutaway view of the POC, showing a main board 21 having an MPU mounted inside the housing and an interface cage 22 and A for mounting various interface boards.
A C / DC power supply 14, a floppy disk driver 9, a hard disk 11, an external signal connector section 13 and a SCSI bus cable 12 are arranged. In the present embodiment, the external signal connector section 13 is arranged below the floppy disk driver 9 and externally arranged. The signal connector 18 is arranged on the lower front surface of the floppy disk driver 9, and the cover 23 is arranged on the front surface. As a result, as shown in FIG. 5, the external signal connector 18 is not covered by the cover 23 and is not easily operated during normal process operation.
On the other hand, at the time of maintenance, the external SCSI bus compatible device can be easily connected only by removing the cover 23 and connecting the external signal cable.

In this embodiment, one end of the SCSI bus is the hard disk interface 10 and the other end is the external signal connector portion 13. However, this is not a limitation. The hard disk 11 is used as one end and the SCSI bus terminating device is attached, and then the hard disk interface 10 is connected. Place
Further, the same result can be obtained by using the external signal connector portion 13 at one end on the opposite side.

[0012]

According to the present invention, S for connecting a hard disk for maintenance of the POC hard disk
An external signal connector that connects an external SCSI bus compatible device to the extension line of the CSI bus can automatically perform complicated bus matching of the SCSI bus by connecting only one signal cable to the external signal connector. It is possible to shorten the raising time, and also to detect the presence or absence of the external connection cable and disconnect it to the SCSI bus terminator based on it.
The cost of the maintenance part of the OC can be reduced, and the reliability of the SCSI bus terminator can be improved because it is not necessary to remove and forget to attach the SCSI bus terminator during maintenance.

[Brief description of the drawings]

FIG. 1 is a block diagram of a process operator's console.

FIG. 2 is a SCSI bus connection diagram when connecting an external SCSI bus compatible device.

FIG. 3 is a SCSI bus connection diagram during normal process operation.

FIG. 4 is a sectional view of the inside of the POC control unit.

FIG. 5 is a front view of a POC controller.

[Explanation of symbols]

13 ... External signal connector part, 18 ... External signal connector,
19 ... External signal cable connection presence / absence detection circuit, 20 ... SC
SI Buster Minator disconnection and connection circuit.

Claims (1)

[Claims] 1. A process operator's console, which is a man-machine part of a process control system for process control, and a hard disk having a microprocessing unit as a control core and a SCSI bus interface as an external storage device of the microprocessing unit. And the hard disk interface and the hard disk of the micro processing unit
A signal connector that is connected by an SI bus and that has a SCSI bus terminator that matches the SCSI bus at one end on the SCSI bus and that is externally connected to the opposite end that is connected to the SCSI bus terminator and the signal connector External signal cable connection presence / absence detecting means for detecting presence / absence of connection of the external signal cable, and a SCSI bus for disconnecting the SCSI bus terminator of the signal connector from the SCSI bus based on the result of the external signal cable connection presence / absence detecting means. A process operator's console comprising a terminator disconnecting means and automatically switching the SCSI bus terminator by connecting the external signal cable.