JPH0129464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a device that connects a main station and a plurality of slave stations with a two-wire transmission line and performs data transmission.

(2) Prior art Slave stations have the function of inputting and inputting a large number of process variables such as temperature, or inputting or outputting field data such as operation output to the operating end, but the operating conditions of these slave stations can be set over a wide range of It was extremely troublesome to perform this for each subsidiary station that was scattered over a wide area.

(3) Purpose of the Invention In view of the above points, the purpose of the present invention is to provide a transmission device in which the operating conditions are set at the main station, and the settings and changes are facilitated.

(4) Embodiment of the Invention FIG. 1 is a configuration explanatory diagram showing an embodiment of the invention.

In the figure, 1 is a main station that performs transmission with slave stations and controls transmission with slave stations, 2 is a plurality of slave stations (one in this example) that inputs and outputs field data, and l
is a two-wire transmission line for connecting the main station 1 and the slave station 2 for data transmission.

The master station 1 includes an input section 11 including keys and indicators for setting the operating conditions of each slave station 2, a memory section 12 for storing the operating conditions set by the input section 11, and an arithmetic control section for managing and controlling the overall operation. 13. Consists of a transmission unit 14 that transmits and receives data signals, etc., and the slave station 2 includes an input/output unit 21 that inputs or outputs field data, a memory unit 22 that stores operating conditions from the master station 1, and a data calculation unit. It is composed of an arithmetic control section 23 that performs control, and a transmission section 24 that transmits and receives data signals.

The operation of n slave stations will be explained with reference to FIG.

First, a part or all of the operating conditions of each slave station 1, 2, ..., n are set in the main station 1, and this operating condition data is sequentially transmitted to each slave station 1, 2, ..., n,
Each slave station 1, 2,..., n transmits a signal (ACK) indicating that it has completed receiving the operating conditions to the master station 1 (see Figure 2).
,). Next, the process shifts to normal data transmission, and the master station 1 sends a polling signal (POL) to each slave station 1, 2, ..., n in sequence, and the slave stations 1, 2, ..., n collect and transmit the input data. Send to main station 1 (,
,). During operation, if the slave station 1 loses the operating conditions due to a power outage, for example, and needs the operating conditions, it transmits a request to set the operating conditions to the master station 1 in response to a polling signal from the master station 1 (). Then, the operating conditions are transmitted to the slave station 1 by the next polling from the master station 1, and normal operation continues (,).

In this way, since the parameter download method is used in which the operating conditions of each slave station are set in advance by the master station, it is easy to set and change the operating conditions. Note that the unique hardware input or output range of each slave station is fixed to a predetermined value.

By the way, the operating conditions of main station 1 can be set using the key
In addition to the man-machine interface using the input section 11 such as a display, settings may be made by an external computer via a computer interface, or may be made by an input device such as a floppy desk or magnetic tape. It's good to wear.

Furthermore, the transition from the operating condition setting state to normal input or output data transmission may be performed automatically by an external command or after the setting is completed.

It is also possible to request the operating conditions from the slave station to the master station, and if the operating conditions are changed during normal operation, the operating conditions are immediately transmitted to each slave station, and then the input/output data is automatically transmitted again. to move to.

(5) Summary of the Invention As described above, the present invention allows a master station to set some or all of the operating conditions of all slave stations.
After transmitting the operating condition data from the master station to each slave station,
This is a transmission device that shifts to normal input or output data transmission.

(6) Effects of the invention Since the operating conditions of all slave stations are set at the master station, operation can be started and operating conditions can be changed even if slave stations are distributed over long distances, at high places, in vicious circles, etc. It's easy. Note that if the slave station does not have backup measures against power outage, by requesting the operating conditions from the master station upon power restoration, the burden on the slave station can be reduced and the cost of the entire device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, and FIG. 2 is an operation explanatory diagram. 1...Main station, 2...Slave station, l...2-wire transmission line.

Claims (1)

[Claims] 1. In a transmission device that includes at least one slave station having an input or output function and a master station that is connected to this slave station via a two-wire transmission line and transmits data, the operation of all slave stations After setting some or all of the conditions on the master station and transmitting the operating condition data from the master station to each slave station, an external command or automatic transition to normal input or output data transmission occurs. If a slave station requests operating conditions from the master station while output data is being transmitted, the master station immediately transmits the operating conditions to the slave station and then automatically shifts to input/output data transmission again. Characteristic transmission equipment. 2. The transmission device according to claim 1, wherein the main station is provided with a man-machine interface such as a key and a display for setting operating conditions. 3. The transmission device according to claim 1, wherein the main station is provided with a computer interface, and operating conditions are inputted from an external computer. 4. The transmission device according to claim 1, wherein the main station is provided with an input device such as a floppy disk or magnetic tape, and the operating conditions are set using this input device.