JPH0766395B2 - Data transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a data transmission device using a digital computer and a digital control device.

(Prior Art) In a recent plant control system, an operator employs a CRT operation in which a light pen or a keyboard is used to perform an operation, and a digital computer (hereinafter, referred to as a computer) and a data received from the computer are received. Digital controller for controlling the plant (hereafter
It is called a control device).

FIG. 3 is a diagram showing data transmission between a conventional computer and a control device.

In FIG. 3, data transmission is performed between the computer 1 and the control device 2. The transmission data area 3 of the computer 1 was prepared for the number of items of transmission data, and the reception data area 4 of the control device 2 was prepared to be the same area as the transmission data area 3.

Here by operator 5 by CRT 6 and keyboard 7
When the value of the data of B is changed by the CRT operation, the changed new data is transmitted from the computer 1 to the control device 2, and the received data area 4 of the control device 2 is transmitted.
The value of the register accommodating the B data in is replaced with the changed new data.

The register storing each data in the reception data area 4 of the control device 2 holds the data once the data is input, and the data up to that time is not updated until the next data comes. The transmission capacity from the computer 1 to the control device 2, that is, the capacity of the transmission data area 3 was proportional to the number of items of data required for transmission.

(Problems to be solved by the invention) When the control system is fully adopted for the CRT operation and the distributed control is performed along with the enlargement of the plant, as shown in FIG. Device 2
Will be connected by data transmission.

As described above, when the number of control devices 2 increases and the number of transmission data transmitted from the computer 1 to the control device 2 increases, the area of the transmission data area 3 of the conventional computer 1 must be made very large. However, since the transmission data area 3 is limited, a problem that the transmission capacity cannot be increased occurs and a large-scale control system cannot be constructed.

Even if the computer 1 can be constructed, increasing the transmission data area of the computer 1 imposes a heavy burden on the computer 1 and adversely affects the performance.

An object of the present invention is to provide a data transmission device capable of coping with an increase in the number of items of data transmission without increasing the transmission and reception data areas.

[Structure of Invention]

(Means for Solving the Problems) In the CRT operation, an operator usually changes certain data by operating a keyboard or a light pen. In this case, changing data means changing one data by one operation. On the other hand, since the transmission time from the computer to each control device is much faster than the operation by the operator, one data is transmitted to the control device each time the operator operates the CRT operation. Even if there is a time delay when transmitting the change data one by one as compared with the case where the change data is transmitted all at once, this is because the human being
Since they are input one after another, the time delay does not matter.

Here, as shown in FIG. 2, a number is assigned in advance corresponding to each item of the transmission data, and a register group for accommodating each transmission data in order of the numbers is prepared on the control device side.

When the operator changes a certain data by the CRT operation, the computer transmits only the data changed by the operator and the two data having the numbers determined in correspondence with the items of the transmission data to the control device. Next, the control device receives the above two data sent from the computer, reads the number attached to the data, and stores it in the register corresponding to the above number among the transmission data storage registers prepared in the control device. The new received data changed by the operator is stored.

(Operation) Since the transmission data transmitted from the computer to the control device may be only the data changed by the operator and the number indicating which number of the transmission data item the data corresponds to in advance, the number of transmission data items is Even if the number increases, the number corresponding to the item of data only increases, and the data area for transmission and reception does not increase. On the contrary, it is possible to reduce the number compared to the conventional case.

(Embodiment) FIG. 1 is a view showing an embodiment of the present invention.

In FIG. 1, a transmission data area 3 is provided inside the computer 1.
And a transmission data item number program 8 in which a predetermined number is registered for each transmission data item. Inside the control device 2, a reception data area 4 and a data transfer program 9 for storing the reception data from the computer 1 in a predetermined register and a transmission data storage register arranged in accordance with a predetermined order of each transmission data item. There are 10 groups. FIG. 2 is a table showing predetermined transmission data items and corresponding numbers. FIG. 2 shows that the number of transmission data items is from A to N, and the numbers are assigned from 1 to 14 in one-to-one correspondence.

Here, a case where the operator 5 changes the data of the B data item in the transmission data items will be described. First, the operator 5 changes the data of B using the CRT 6 or the keyboard 7.

The changed data means the changed B data and the second because the transmission data item program 8 in the computer 1 corresponds to the transmission data item B in advance as shown in FIG. The numerical value “2” to be transmitted is sent to the transmission data area 3.

From the transmission data area 3 of the computer 1, only the data B and the numerical value 2 are transmitted to the control device 2. The reception data area 4 of the control device 2 may be an area of the same size as the transmission data area 3 and receives the data B and the numerical value 2. For the data received in the reception data area 4, the numerical value 2 is read by the data transfer program and the data of B is transferred to the second register in the transmission data storage register group 10.

In addition to the above-mentioned embodiment, it is also possible to use symbols such as A, B, C in addition to the numerical values of the numbers to correspond to the transmission data items.

Further, if the total data of the transmission data and the numerical value of the number corresponding to the data is within 16 bits, the data transmitted from the computer to the control device becomes only one word, and the transmission amount can be further reduced.

〔The invention's effect〕

As described above, according to the present invention, the transmission capacity transmitted from the computer 1 to the control device 2 is not affected by the number of transmission data items and can be sufficiently applied to a control system having a large number of transmission data items.

When the number of transmission data items increases, the transmission area to be transmitted from the computer 1 to the control device 2 is required for the number of items of the transmission data unless the present invention is used, whereas only the change data and its transmission data item number according to the present invention are required. Therefore, the amount of transmission and transmission can be extremely reduced, so that the load on the computer 1 can be reduced and the performance of the computer 1 can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing transmission data items and corresponding numbers, FIG. 3 is a diagram showing data transmission between a conventional computer and a control device, and FIG. The figure is 1
It is a figure which shows the connection of one computer and a some control apparatus. 1 ... Computer, 2 ... Control device 3 ... Transmission data area, 4 ... Reception data area 5 ... Operator, 6 ... CRT 7 ... Keyboard

Claims (1)

[Claims] 1. A transmission device having a transmission data area for storing transmission data and a predetermined numerical value or symbol corresponding to the transmission data, and transmitting the numerical value or symbol corresponding to the transmission data at the same time. , A receiving data area having the same size as the transmitting data area for receiving the numerical value or symbol corresponding to the transmitting data from the transmitting device, and a numerical value or symbol corresponding to the transmitting data received in the receiving data area. A data transmission device comprising a reception device having a transfer unit for transferring and storing the transmission data in a predetermined storage area.