JPH0340596A - Remote process input output system - Google Patents

Abstract

PURPOSE:To ensure a high speed response by providing a prescribed relation between an interrupt input signal and a state signal relating to the interrupt input signal, using the interrupt input signal and the state signal in pairs and sending the pair to a computer with preceding over the periodic transmission. CONSTITUTION:The remote process input output system consists of a computer 1, a computer side station 2, a remote station 4, a transmission system 5, and a setting panel 6. Then a prescribed relation is set between an interrupt input signal required urgently to be sent to the computer 1 and a state signal having a close relation to the interrupt input signal, and the interrupt input signal and the state signal in a prescribed relation to the interrupt input signal in pairs are sent to the computer 1 with precedence over the periodic transmission. Thus, the deviation between the interrupt input signal and the state signal in close relation to the interrupt input signal is avoided and the remote process input output system securing high response is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is a remote process input device for reading the status of a process installed far from a computer into a computer, or for outputting output data from a computer to a distant process. This concerns the output method.

[Conventional technology]

Conventionally, devices that read the status of a process installed far from a computer into a computer, such as a telemeter, periodically transmit ill-side status signals from the remote side to the computer side, and On the side, this signal is sent to buffer memory 1.
By reading the contents of this buffer memory, a program on the computer side can learn the status of a distant process.

Figure 3 is a configuration diagram of the process input/output device that is the subject of this patent, where (1) is the computer, (2) is the computer side station, and (3) is the state of the process mapped as needed. Computer stage 1 (buffer memory 2 in 21)
4) Remote station must be installed in a remote location.

[5] is a transmission system that connects the computer station and remote station in a loop; (6) is a setting panel that is connected to the remote station and is subject to process input/output;
(6a) is located on the setting board and is a data setting switch for setting setting values, and (ab) is a read button for reading the set data into the computer.

FIG. 4 shows the frame format of the signal flowing on the transmission system (5), and is sandwiched between synchronization signals and commands that indicate to the computer the distinction between input, 2 interrupts, and output.

A point number that distinguishes a group of status signals or interrupt codes, a status signal consisting of an 8-bit bit pattern that indicates the process status, and an interrupt code that also consists of an 8-bit pit pattern that indicates the source of the interrupt. It consists of

FIG. 5 shows a buffer memory installed in the computer side station (5), and the upper two fingers (hexadecimal numbers) of the address correspond to the point number in the frame format.

Next, the operation will be explained. Top computer stay! ,/!
Input (2) sends out the command-011 point number (00), which is cyclically repeated from s to FF)+@, following the synchronization signal. Remote stage 1 (4) is assigned a point number in advance, and the state of the process of the corresponding point number is placed on the frame. By repeating this operation, the state of the process on the remote station (4) is mapped to the buffer memory (3) of the computer station (2). Computer stage shin (2) is
Also, send 11 commands at an appropriate interval (for example, 100m5).
) and poll for interrupts. At this time, the remote stage processor (4), which needs to notify the computer program of changes in status, etc., places an interrupt code on the frame. As a result, the computer station (2) interrupts the 2M contact computer (1) without going through the buffer memory (3). Using this interrupt signal and interrupt code, the computer program can learn the status of the related process by reading the contents of the buffer memory (3). Note that in the above description of the operation, the description of the operation regarding output command=10 is omitted because it has no relation to the present invention.

[12111 to be solved by the invention] However, in the conventional device, the interrupt signal is sent with priority over the status signal, so when reading the related status signal by the second interrupt signal, the buffer in the computer stage The state data in memory is
It had the disadvantage that it was old data and could not be synchronized with the 2nd interrupt signal. Let me explain this point a little more specifically.

Now, in the configuration diagram shown in FIG. 3, the contents of the data setting switch (6a) are expressed, for example, in a BCD code, and the contents are periodically transmitted to the buffer memory +31 of the computer station [2+] via the transmission system (5). It is loaded. On the other hand, the content of the read button (6b) is assigned to an interrupt input, and when this button is inserted, an interrupt enters the computer, and the computer program uses this signal and interrupt code to determine which read button was inserted. Knowing this, he goes to read the contents of the data setting switch (6m) into the buffer memory (3), but since interrupt signals are transmitted with priority over periodic data, the contents of the data switch read by the computer program 2 are Timing may occur where the data is before setting. In this case, we will explain the human movement, and if the data change is due to the movement of two machines, then
Timing-wise, it gets tough.

In order to avoid such erroneous inputs, in conventional systems like this, a time delay is added to the computer program.
Data was read after a certain period of time (data read cycle) after the interrupt signal was received. This method has the disadvantage that it is not suitable for control systems that require high response.

The present invention has been made to solve the above-mentioned problems, and it is possible to eliminate the gap between one interrupt signal and the status signal related to the interrupt signal, and to ensure high-speed response. The purpose is to obtain remote process input/output devices.

[Means to solve the problem]

The remote process input/output method according to the present invention establishes a certain relationship between an interrupt input signal that needs to be urgently transmitted to a computer and a status signal that is closely related to the interrupt input signal. input signal.

The interrupt input signal and a status signal having a certain relationship are combined and transmitted to the computer with priority given to one-period transmission.

[For production]

The remote process input/output method in this invention synchronizes the 2nd interrupt value with the state signal associated with the interrupt signal, and the state signal at the time the 2nd interrupt occurs is actually read into the computer program. A situation where a discrepancy occurs between the state signal and the state signal can be avoided.

[Embodiments of the invention]

FIG. 1 shows a transmission format for interrupt input according to the present invention. The command is 1 byte and is the 11th one.

The point number is 1 byte and distinguishes groups of interrupt codes and status signals that follow. The interrupt code transmits the cause of the interrupt as one byte of data.

The status signal does not exist on the main frame in the conventional method, and is the key point of the present invention.
Transmit 5 bytes continuously.

The main points of the invention will be explained below according to examples.

Here, as shown in Figure 2, the interrupt code and the point number of the status signal are 3-digit hexadecimal numbers, and the number whose last digit is 0 is used as the interrupt data. Allocate up to l. to state data and have a certain relationship.

When an interrupt signal is generated, 15 bytes of status data whose upper two digits of the point number to which the interrupt code belongs are read and transmitted to the computer station on a 2-interrupt transmission frame.

In stage 1 on the computer side, the state data is stored in the corresponding buffer memory (3), and an interrupt is generated in the computer along with an interrupt code. In this way, by establishing a certain relationship between interrupt data and status data in advance, and selecting point numbers using this relationship depending on the actual application, status data related to interrupt data can be At the same time, the data is sent to the computer, and the computer program can obtain the out-of-sync data by reading the relevant state data from the buffer memory using an interrupt signal.

In the above embodiment, 15 status signals are associated with one 2-interrupt code, but this number can be varied in various ways. Furthermore, in the embodiment of the present invention, the two interrupt codes and status signals are made to correspond to each other under the condition that the upper two digits match.

Various pariege methods can be considered to deal with this, and achieve the same effect.

〔Effect of the invention〕

As described above, according to this invention, the price number is 20%.

A certain relationship is established between the interrupt signal and a related status signal, and the interrupt input signal and the status signal are paired and transmitted to the computer with priority over two-periodic transmission. Therefore, there is no discrepancy between the interrupt signal and related status signals, and a remote process input/output method that ensures high-speed response can be obtained.

[Brief explanation of drawings]

FIG. 1 shows a frame format for an interrupt input signal in a remote process input/output method according to an embodiment of the present invention, FIG. 2 shows the contents of a computer buffer memory showing the association between the interrupt input signal and a status signal, and FIG. 4 is a block diagram of a process input/output method, FIG. 4 is a frame format of a conventional transmission system, and FIG. 5 is a configuration diagram of a buffer memory in a conventional computer station. In the figure, till is the computer, (2) is the computer stage, (31 is the memory, (411, t station), (5) is the transmission system, (6) is the setting panel, (6a) is the data setting switch, (eb) is an interrupt button.

Claims (1)

[Claims] A computer, a process input/output device installed remotely from the computer, a transmission system for connecting the computer and the process input/output device, and a buffer installed on the computer side for storing images of process data. In a system that uses the transmission system to periodically read process data into the buffer memory, an interrupt input signal that needs to be transmitted to a computer and a system related to the interrupt input signal A certain relationship is established with a certain state signal, and the interrupt input signal and a state signal that has a certain relationship with the interrupt input signal are paired and transmitted to the computer with priority over periodic transmission. A remote process input/output method characterized by: