JPS60125038A - Local area network - Google Patents

Abstract

PURPOSE:To allow a terminal station to know a line operation state and yield by storing the operation state of equipment in the terminal station as digital signal data, and sending it in response to a data request signal from another station. CONSTITUTION:The input processing circuit 10-1 of input terminal equipment 4 calculates the instantaneous value, mean value, maximum value, and minimum value of digitally exchanged data. Those data are stored in a nonvolatile RAM 11. When those data are known, which data on terminal equipment is specified by a personal computer 14 and then a request signal is sent from a control circuit 18 through a data bus 1. The input terminal equipment 4 detects the request signal being addressed to the terminal on the basis of the request signal and sends it to a terminal station 3 together with its address as an attribute. Consequently, the operation states of equipment distributed on a line are brought under the centralized control of the personal computer and system control is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a local area network capable of promoting factory automation and the like.

[Technical background of the invention]

In equipment such as factories and plants, when recording and managing the output of instruments that monitor the status of equipment, such as current needles, voltage needles, phase meters, flow rate needles, pressure needles, and water level meters, it is necessary to A common configuration method is to connect a dedicated recording needle and monitor device for aggregating and recording data.

In recent years, as part of the automation of factories and equipment, highly reliable information transmission that can connect microcomputers for machine control and personal computers for production management and quality control to form a local area network at the production site has been developed. Systems are being proposed.

When controlling equipment such as manufacturing machines and processing machines by configuring a local area network, it is desirable to be able to manage the operational status of the machines or the status of the equipment to be controlled.

For example, power consumption of equipment 1. By managing and analyzing voltage, current, and equipment conditions such as pressure, flow rate, and water level, it becomes possible to know whether equipment efficiency, load sharing, and control are being performed effectively.

[Purpose of the invention]

The purpose of the present invention is to meet such demands, and the operating status and status of devices are stored in the non-volatile RAM of the input terminal installed for each device, and the data at the terminal station is stored. The object of the present invention is to provide a local area network capable of transmitting data to a requested personal computer when a data request signal is received from a collecting personal computer.

[Structure of the invention]

The local area network of the present invention includes an A/D converter that converts an analog electrical signal of monitored equipment into a digital quantity, and an instantaneous value processing means that calculates the instantaneous value of the electrical signal converted to the digital quantity. Input processing means for each input channel includes an average value processing means, a maximum value processing means, and a minimum value processing means for calculating the average value, maximum value, and minimum value of the electrical signal, respectively; The present invention is characterized by comprising: a non-volatile RAM that stores electrical signal data; and a transmission control means that transmits the requested data from the non-volatile RAM in response to a transmission request from another terminal station.

〔Example〕

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 shows an example of a local area network configured according to the present invention, where (1) is a data bus, (2) is a data bus, and (2) is a data bus.
) is a central control station, (3) is a terminal station, (4) is an input terminal, and (5-1) and (5-2) are A/D converters.

The input terminal (4) includes an A/D converter (5-1) that converts analog data for each channel into a digital signal.
, (5-2) is prefixed, and the digital signal is sent to the input processing circuit (10-1), (
10-2). Each input processing circuit is provided with an instantaneous value processing circuit (6), an average value processing circuit (7), a maximum value processing circuit (8), and a minimum value processing circuit (9),
They are each configured to calculate an instantaneous value, an average value, a maximum value, and a minimum value of the input signal.

These values are stored in non-volatile RAM (11).

(12) is a transmission control circuit, which transmits data using a method described later.

In addition, the terminal station (3) is equipped with a data collection device (13), which includes command decoding means (15) for decoding commands from the personal computer (14), and non-volatile R for transmission.
An AM (16), a receiving nonvolatile RAM (17), and a transmission control circuit (18) are provided.

Next, the operation of the present invention will be explained.

In each input terminal (4), data representing the status of equipment such as machine tools is sequentially stored in the non-volatile RAM (11), so if you want to know the data, you can use the personal computer (14).
) to specify which data of which input terminal device is desired. The transmission request signal is sent from the transmission control circuit (18) via the data bus (1).

The input terminal (4) detects that the address of the request signal is its own, and sends the data stored in the non-volatile RAM (11) to the terminal station (3) with its own address attached. Send. The data is received by the terminal station (3) that issued the data transmission request, and sent to the computer (14).
is input.

Note that a data transmission request can be issued in the same manner from a personal computer of another terminal station, and the input terminal that has received the data request will send the data to the personal computer that has requested the data. Therefore, it is possible to receive contact data from any terminal station through the data bus (1).

The data thus received is displayed on the CRT screen of the personal computer (14) of the terminal station (3) and, if necessary, is output to an attached printer.

The personal computer (14) can monitor momentary fluctuations in data from the instantaneous value of the input signal. Further, when a request is made to send an average value, the average value within a specified time period is calculated and transmitted by the personal computer (14). Further, the maximum value and minimum value are calculated and transmitted as the maximum value or minimum value within a specified time period.

By receiving such a value, the computer (14)
With this, you can monitor the status of devices and controlled objects, record them on a printer attached to your computer, or store the contents in an external storage device.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to centrally manage the operating states of devices and control objects distributed on a line using a personal computer, and thereby the situation can be grasped, analyzed, and countermeasures can be taken. It is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a local area network configuration according to the present invention, and FIG. 2 is an explanatory diagram showing a method of transmitting contact data. (1); Data bus (2): Central control station (3): Terminal station (4): Input terminal (5-1), (5-2)? A/D converter (6): Instantaneous value processing circuit (7): Average value processing circuit (8): Maximum value processing circuit (9): Minimum value processing circuit (10-1), (10-2): Input Processing circuit (11
) : Non-volatile RAM (12) : Transmission control circuit (1, 3) : Data collection device (14) ? Personal computer (15): Command decoding means (16): Non-volatile RAM for transmission (17): Non-volatile RAM for reception (18): Transmission control circuit license applicant: Computer Technica Rijin Co., Ltd. Masu Tegori (and 2 others) Procedures Amendment □ April 26, 1980 Patent No. 233169 No. 2, Name of the invention Local area network 3, Side thread with the case of the person making the amendment Patent applicant address name Name Computer Technica Co., Ltd. 4 , Agent 7, Contents of amendment: Engraving of all drawings (no change in content)

Claims (1)

[Claims] 1. An A/D converter that converts an analog electrical signal of a monitored device into a digital quantity, and an instantaneous value processing means that calculates the instantaneous value of the electrical signal converted to the digital quantity. Input processing means for each input channel includes an average value processing means, a maximum value processing means, and a minimum value processing means for calculating the average value, maximum value, and minimum value of the electrical signal, respectively; What is claimed is: 1. A local area network comprising: a nonvolatile RAM that stores electrical signal data; and a transmission control means that transmits requested data from the nonvolatile RAM in response to a transmission request from another terminal station.