JPH0298298A - Control system - Google Patents

Abstract

PURPOSE:To prevent mis-control by driving a control request signal into two data, sending it to other controller via a scan transmitter and reproducing a control request signal from other data when the data satisfy an AND condition in the other controller. CONSTITUTION:A central control unit 1 generates a control request signal and a split section 6 prepares two data from the control request signal and writes them into an internal memory. A central side scan transmitter 2 sends the content written in the internal memory of the central controller 1 onto a scan transmission line 3 sequentially. Moreover, a field side scan transmitter 4 fetches the data on the scan transmission line 3 synchronously with the central side scan transmitter 2. A field side controller 5 uses an AND condition discrimination section 7 to check whether or not each data satisfied the AND condition and when the data satisfying the AND condition exists, a control request signal corresponding to the data is reproduced to control the field device. Thus, even if noise is invaded on the transmission line, mis-control of the control object device is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a control system used when remotely controlling a device to be controlled using a solid device.

(Prior Art) A control system shown in FIG. 5 is conventionally known as a control system for remotely controlling a device to be controlled using a solid device.

The control system shown in this figure includes a central controller 101 that generates a control request signal as shown in FIG. 6(a) when it is necessary to control a device to be controlled; When this is taken in, Figure 6 (b
) as shown in FIG.
a field-side scan transmission device 104 that captures data when it is supplied from the field-side scan transmission device 1;
Figure 6(c) after receiving the data imported by 04.
and a field control device 105 that reproduces a control request signal as shown in FIG. 6(d) and generates a contact signal as shown in FIG. We are prepared.

Then, when it is necessary to control the equipment to be controlled (field equipment), the central control device 101 generates a control request signal to remotely control the field equipment.

(Problem to be solved by the invention) By the way, in such a control system, the transmission line 1
When some kind of abnormality occurs in 03 etc., Fig. 7 (a)
, even though no control request signal or data is output from the central control device 101 or the central scan transmission device 102 as shown in FIG. When pseudo data due to noise is supplied, the field control device 105 may mistakenly believe that the control request signal is coming from the solid device 101 and output a contact signal as shown in FIG. 7(d).

For this reason, when the equipment to be controlled is equipment constituting an electric power plant or the like, there is a risk of causing a major accident such as a power outage or a shutdown of the plant.

In view of the above circumstances, it is an object of the present invention to provide a control system that can prevent equipment to be controlled from being erroneously controlled even when noise or the like enters a transmission path or the like.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, a control system according to the present invention includes a plurality of control devices and a scan transmission device that connects each of these control devices. The control device side divides one control request signal into two pieces of data and transmits these data to another control device via the scan transmission device, and the other control device transmits the data via the scan transmission device. It is characterized in that when two data are supplied, it is determined whether or not these data satisfy an AND condition, and when these data satisfy an AND condition, a control request signal is reproduced from the data.

(Function) In the above configuration, the control device on the transmitting side divides the control request signal into two pieces of data, supplies these data to another control device via the scan transmission device, and sends these data via the scan transmission device. The other control device that receives the data determines whether or not these data satisfy the AND condition, and when these data satisfy the AND condition, reproduces a control request signal from the data.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a control system according to the present invention.

The control system shown in this figure includes a central control device 1 that is the center of the system, and a site control device 5 that is installed on the site and controls site devices (devices to be controlled) provided in various parts of the site.
, a scan transmission path 3 laid from the solid device 1 side to the field control device 5 side, and a central scan transmission device interposed between one end of this scan transmission path 3 and the central control device 1. 102, and a field-side scan transmission device 104 inserted between the other end of the scan transmission path 103 and the field control device 105.

When it becomes necessary to control the field equipment, the central control device 1 generates a control request signal as shown in FIG. 2(a), and also sends a control request signal as shown in FIG. As shown, two data (first, second
data) and write them into an internal memory (not shown).

Further, the central scan transmission device 2 is configured to perform scan transmission at a preset period, and sequentially reads out the contents written in the internal memory of the central control device 1 and transfers them to the scan transmission path. 3 Send above.

In this case, since two pieces of data are written in the internal memory, two pieces of data (first and second data) are output from the central scan transmission device 2 and sent onto the scan transmission line 3. .

The field-side scan transmission device 4 is configured similarly to the central scan transmission device 2, and performs scan transmission processing in synchronization with the central scan transmission device 2 to transmit data on the scan transmission path 3. is taken in and written into the internal memory (not shown) of the field control device 5.

In this case, on the scan transmission line 3, as shown in FIG. 2(d),
Since the first data and the second data are loaded as shown in (e), the field-side scan transmission device 4 takes in these data and writes them into the internal memory of the field control device 5.

The field control device 5 checks whether each data written in the internal memory satisfies the AND condition by the AND condition determination unit 7, and if there is data that satisfies the AND condition, it issues a control request corresponding to this data. The signal is regenerated and the contact 8 is turned on to generate a contact signal and control the field equipment.

In this case, since the AND condition is whether or not the two data were written with a time difference within the transmission scan time, the first data, the second data When the data are written at the same time, the field control device 5 determines that the first data and the second data have been output from the central control device 1 based on the check result of the AND condition determination section 7, as shown in FIG. 2(f). As shown in FIG. 2(g), a control request signal corresponding to these first and second data is generated, and the contact 8 is turned on based on this control request signal to generate a contact signal as shown in FIG. Control field equipment based on contact signals.

In this embodiment, the control request signal generated by the central control device 1 is divided into two pieces of data within the central control device 1, and these are sent to the central scan transmission device 2,
The data is sequentially supplied to the field control device 5 via the transmission line 3 and the field-side scan transmission device 4, and the field control device 5 performs an AND operation on these two data to control the field equipment. As shown in FIG. 3(a) and (b), even when noise etc. is mixed into the scan transmission line 3 and multiple pseudo data are supplied to the scan transmission device 4 on the field side, as shown in FIG. 3(c). It is possible to prevent the control signal from being output from the field-side scan transmission device 4, thereby preventing erroneous control of field equipment.

In other words, in this embodiment, we focus on the fact that two pieces of data due to noise do not occur simultaneously during the scan transmission time. Even when random data is supplied, this data is canceled to prevent the field control device 5 from malfunctioning.

Furthermore, in the embodiment described above, the central controller 1 creates two pieces of the same data from one control request signal, but as shown in FIG. Data (original data) and data obtained by inverting this data (inverted data) are created, and these are sequentially transmitted to the field control device 5 via the central scan transmission device 2, the scan transmission path 3, and the field scan transmission device 4. The control request signal may be reproduced on the condition that the original data and the inverted data are available.

With this configuration, even if noise such as two bits rising at the same time occurs, it is possible to prevent the field control device f5 from erroneously controlling the field equipment.

Further, in each of the embodiments described above, the present invention has been explained by taking as an example a case in which a control request signal is supplied from the central control device 1 side to the field control device 5 side, but the present invention is not limited to such a case. It is obvious that this method is effective for transmitting signals from the field control device 5 side to the central control device 1 side, and for exchanging control signals between all other control devices.

〔Effect of the invention〕

As described above, according to the present invention, even when noise or the like enters a transmission path, it is possible to prevent a device to be controlled from being erroneously controlled.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the control system according to the present invention, FIG. 2 is a timing chart for explaining an example of the operation of the embodiment, and FIG. 3 is a diagram for explaining an example of the operation of the embodiment. FIG. 5 is a schematic diagram showing another embodiment of the control system according to the present invention, FIG. 5 is a block diagram showing an example of a conventional control system, and FIG.
5 is a timing chart for explaining the operation of the control system shown in FIG. 5, and FIG. 7 is a timing chart for explaining problems in the control system shown in FIG. 5. 1...Control device (central control device) 2...Central side scan transmission device 4...Site side scan transmission device 5...Control device (field control device)

Claims (1)

[Claims] (1) In a control system equipped with multiple control devices and a scan transmission device that connects each of these control devices, the control device, which is the sending side, divides one control request signal into two pieces of data and transmits these data. is transmitted to another control device via the scan transmission device, and the other control device determines whether or not these data satisfy the AND condition when the two data are supplied via the scan transmission device. A control system characterized in that a control request signal is reproduced from the data when the data satisfies an AND condition.