JPS6028459B2 - Data transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission method for transmitting information via a loop transmission path.

Since a process control device has a large number of scattered input/output devices such as sensors and a data processing device that processes the information, a data transmission device equipped with a loop transmission path that requires a small amount of cables to interconnect these devices, A so-called data way system is often used.

FIG. 1 shows a connection diagram of a conventional data transmission system. In FIG.
It is sent to a. FIG. 2 will be explained. Frame 5 is
a synchronization slot SYN for synchronizing each data station 2, 3 and 4;
It has data slots SLTI to SLTn uniquely allocated to data slots 3 and 4 (assuming n=4). Each data slot SLTI to SLTn includes a flag F indicating that it is used, a control flag CONT indicating the category of information inserted into the data DATA, and each area of the data DATA into which information to be transmitted is inserted. has. Referring again to FIG.

The data stations 2, 3 and 4 are connected to process line control devices (hereinafter referred to as pro-controllers) 6, 7 and 8, which are data devices, respectively. Procon 6,7
and 8 are connected to process line 9 for controlling it and for transmitting information via data stations 2, 3 and 4, ie via frames as shown in FIG.
We are giving and receiving. On the other hand, the setting display panel 10 displays the sensor
Cables 10a are attached to the bases 11, 12 and 13, respectively.
10b and 10c, and information is exchanged between them. This information consists of information indicating, for example, on or off depending on the characteristics of the process control device, and is usually small in amount or short. Conventional data transmission systems are configured as described above, and have the drawbacks of low transmission efficiency and poor economic efficiency, as well as poor sensor and
Because the base information has completely different characteristics from the pro-controller information, it is not compatible to transmit both using the same transmission path, and transmission efficiency is improved if both are transmitted using the same format data slot. It had the disadvantage of lowering the The present invention was made in order to eliminate the drawbacks of such conventional methods, and has developed a data transmission method that can transmit all information from the processor, sensor, base, etc. via a loop transmission path and improve transmission efficiency. The purpose is to provide.

The data transmission method of the present invention interconnects the program controller, sensor, base, setting display panel, etc. via a data station connected to a loop transmission path, and also connects each program controller to an address slot that specifies the reception of information. Transmission is carried out via a frame consisting of data slots that are uniquely assigned to each sensor base for transmitting a block of information and data slots that are uniquely assigned to each sensor base for transmitting its respective information.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic connection diagram of the data transmission system of the present invention.
Synchronization station 14 and data station 15~
21 are interconnected via a loop transmission line 14a. The data station 15 includes a setting display panel 22 and a data station 15.
The station 16 has a sensor base 23, the data station 17 has a processor base 24, the data station 18 has a sensor base 25, the data station 19 has a processor base 26, the data station 20 has a sensor base 27, and data station 21
A processor 28 is connected to the . sensor base 23,
25, 27, and the process controllers 24, 26, and 28 are
It is connected to line 9 and exchanges information. FIG. 4 shows the structure of a frame generated by the synchronization station 14.

The frames are sequentially arranged from the left side of FIG.
N, address slot ADR, and each processor controller 24,
Data slots PCI to PCn (however, n=3) are uniquely assigned to each of the sensor bases 23 and 28 and transmit block information, and each of the sensor bases 23 and 2
5, 27 and the setting display panel 22, respectively, and data slots 10 transmit the respective information.
1 to 1 h (however, m=4). FIG. 5 is a block diagram showing details of data station 20, and data stations 16, 18 and 15 also have a similar configuration.

In the figure, the unit 29 includes a unit 30 that is coupled to the loop transmission line 14a and has scanning control and transmission functions via the path 29a, and a unit 31 that has a reception function and a control function that distributes process input/output information. connected to. The unit 30 is connected to a unit 32 inputting the information of the bus 30a and the sensor base 27.
~1~32-n. Unit 31 is bus 3
1a and units 33-1 to 3 for transferring received information
3-n to the sensor base 27. 6th
The figure is a block diagram showing details of data station 19, and data stations 17 and 21 also have a similar configuration. In the figure, the unit 34 is the loop transmission line 1
4a and via the bus 34a, units 35-1, 36-1 for transmitting and receiving block data for the processor and a unit 35 for transmitting and receiving sensor-based data.
-2, 36-2. Unit 35-1, 3
6-1 connects to interface unit 3 via bus 37.
Connected to 8. The units 35-2, 36-2 and the interface unit 38 connect to the processor 2 via the bus 39.
Connected to 6. Here, the unit 35-2 has a process output data memory for the sensor base of the processor 26, and when transmitting data, scans the data memory and transmits the data. Unit 36-2 has an image memory containing a mapping of the data of the process input units to be received. Next, the operation will be explained.

FIG. 7 shows that the unit 300 scans the units 32-1 to 32-n and sends information to the data slot 101 of each frame according to the changes in the contents of the address slot ADR generated by the synchronization station 14. Another station on the aircraft, for example station 19, is shown sending information to data slot 102. In FIG. 9, units 32-1 to 32-1 of stations 20, 18, 16, and 15 are shown.
32-n shows the correspondence between the data sent out by the transmission slot and each address in the received data memory 36-2 of the stations 21, 19, and 17.

That is, for example, 101 slots are allocated as slots for transmission from station 20, and unit 32-
1 to 32-n is an address slot ADR of 0 to (n-
It shows that scanning is performed at the timing of 1) and the data in the corresponding unit is sent to the 101 slot. Furthermore, this transmission slot and its scanning address ADR are the addresses (A10) to (A+
n-1), and indicates that when the corresponding slot number 101 scanning address ADR is detected, the data of the slot 101 will be written to a predetermined address in the reception data memory. . Units 32-1 to 32-n of stations 18, 16, 15
also has the same relationship as above. In particular, the received data memories 36-2 of each of the stations 21, 19, and 17 contain the address A, the slot number 101, and the address (A0n
) and slot number 103 Address (A 10) and slot number 105 and address (A+■) and slot number 1
It has an address change function with 07, and has a function to immediately determine a memory address based on the slot number and address ADR value that came on the bus 34a, and write the data of the slot on the bus 34a to the memory. There is.

Therefore, this received data memory 36-2 can be said to be an image memory having an image of the process input unit data of the stations 20, 18, 16, and 15.

FIG. 10 shows the data sent out from the data memories 35-2 of the stations 21, 19, 17 and the transmission slots, and the units 33-1 to 33-n of the stations 20, 18, 16, 15 in the predetermined transmission slots. This shows an example of address settings for receiving data from and their correspondence. Each of the stations 21, 19, and 17 has a transmittable data area of n words in the process output data memory 35-2. In station 21, addresses (B+0) to (B+n-1) are 35-2-1 to 3.
5-2-n transmission data is being written. In the station 19, transmission data 35-2-1 to 35-2-m are written to addresses (C+0) to (C+m-1). In particular, the x mark in the address (C+m) to (C+n-1) portion indicates that although the data area exists, data to be transmitted has not been written. Station 17 has the address (
Send data 35-2-1 to D+0) to (D+n-1)
35-2-n is written. The data in the data memory 35-2 of each of stations 21, 19, and 17 is stored in station 21 using transmission slot number 104, station 19 using transmission slot number 102, and station 17 using transmission slot number 106. and is transmitted according to the scanning of address slots ADRO~(n-1). In particular, the order in which slot numbers are assigned for transmission is arbitrary. The operations up to this point are performed by the transmitting/receiving unit 34, which has the capability of transmitting and receiving data for each slot in the transmission frame in each of the stations 21, 19, and 17, and the process output data memory 35-2 connected to the bus 34a. .

That is, the transmitting/receiving unit 34
R is received and the contents of the ADR slot are given to 35-2 via the bus 34a, and when the corresponding slot is subsequently received, the slot number is given to 35-2. At this time, 35-2 can immediately create a corresponding memory address based on the slot number and the contents of the ADR slot, read data from that address, and output it to the transmitting/receiving unit 34 via the bus 34a. On the other hand, in order for the units 33-1 to 33-n of the stations 20, 16, and 15 to receive data in the transmission slot, it is necessary to determine in advance which transmission slot number to receive the data at which scanning address in the ADR slot. It is necessary to set it.

In FIG. 10, this setting address is assigned to slot number 1 in units 33-1 to 331m of station 20.
02 and set the address ADR to 0 to (m-1), respectively (102-0 to 102-(m-1) in Fig. 10).
Units 33-1 and 33-2 of station 18 are set to slot number 102 and address ADR is set to 0 and 1, respectively, and unit 33-n is set to slot number 106 and address ADR is set to (n-1). ), unit 33-1-3 of unit 16 of station 16
3-n has slot number 104 and address ADR set to 0 to (n-1), and units 33-1 to 33-n of station 15 have slot number 106 and address AOR set to 0 to (n-1). n-1).
By setting in this manner, in the station 20, the units 33-1 to 33-1m receive data 35-2-1 to 35-21m from the station 19 as received data (in FIG. 10, , 19-35-2-1 to 19-3
5-21m) and the unit 33-n receives data 35-21n of the station 21 as received data, and the station 18 receives the data 35-1 and 33-2 of the station 21 as received data.
, data 35-2-1 and 35-2-2 of station 19 are obtained, data 35-2-n of station 17 is obtained in unit 33-n, and data 35-2-1 and 35-2-n of station 19 are obtained in station 16. Data 35-2-1 to 35-2-n of station 21 is obtained at station 1
5 has units 33-1 to 331n with station 17.
This shows that data 35-2-1 to 35-2-n have been obtained. The above receiving operation is performed by the station 20.
, 18, 16, 15 (sixth transmission/reception unit 29)
(Has the same function as the transmitting/receiving unit 34 in the figure)
, slot number of the transmission slot, slot data, and address A unit 31 having functions of receiving data of slot AD and distributing the received data (distributing the received data to the units 33-1 to 33-n by outputting the received data to the bus 31a). and units 33-1 to 33-n. In the case of reception, for example, the address "0" is assigned to the unit 33-1 in FIG. 5 so that it can receive the data slot 102 with the address "0", so the unit 31 receives the address slot 102.

When it is detected that the contents of the slot ADR are "0", the contents of the data slot 102 can be transferred to the unit 33-1. Details of changes in the contents of address slot ADR generated by synchronization station 14 will now be explained with reference to FIG.

For example, unit 32-1 of data station 20
Information from unit 36- of data station 19
It is also assumed that unit 32-1 is assigned an address and data slot 101 with address slot ADR set to "0". In this case, the image memo for unit 36-2 is “0”.
The information of data slot 101 in the frame of address slot ADR whose content is `` is written.
During the period from when the synchronization station 14 sends out an address slot frame containing "0" to when the frame goes around the transmission path 14a and returns to the synchronization station 14 again, the data station 20 uses the address slot AD. Detects the data slot 101 of the frame where is "0" and inserts information into it.

This frame passes through synchronization station 14 and is transmitted to data station 19. In other words, the synchronization station 14 uses address slots ADR with the same content.
The frame with the following information is sent twice (see Figure 8). In the above embodiment, the address slot ADR is arranged next to the synchronization slot SYN, but they may be any time slot as long as it precedes the data slot 101.

As described above, according to the present invention, the processor and sensor
Since the base information is transmitted through the same transmission path and frame, cables can be saved.

[Brief explanation of the drawings] Figure 1 is a connection diagram of a conventional data transmission system, Figure 2 is a configuration diagram of a frame used in a conventional data transmission system, and Figure 3 is a diagram of a frame configuration used in a conventional data transmission system.
The figure is a connection diagram of the data transmission method of the present invention, FIG. 4 is a configuration diagram of a frame used in the data transmission method of the present invention, and FIG.
Figure 6 is a block diagram of a sensor-based data station, Figure 6 is a block diagram of a processor data station, Figures 7 and 8 are diagrams illustrating the frame of the invention in operation, and Figure 9 is a block diagram of the station. 20, 18, 1
An explanatory diagram showing the correspondence between the data of the units 32-1 to 32-n of units 32-1 to 32-n of units 32-1 to 32-n of units 32-1 to 32-n of stations 21, 19, and 17, and FIG. data memory 35-
2 and transmission slots and stations 20, 18, 16,
FIG. 3 is an explanatory diagram showing the correspondence among the 15 units 33-1 to 33-n. 1, 14...Synchronization station, 2-4, 16-2
1...Data station, 6, 7, 8, 24, 26
, 28... Brocon, 11, 12, I3, 23, 25,
27...Sensor base, 29, 30, 31, 32-1
〜32-n, 33-1〜33-n, 34, 35-1, 3
5-2, 36-1, 36-2...unit, 38...interface unit. In addition, in the figures, the same reference numerals indicate the same parts. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. In a data transmission system in which multiple data stations are connected in series through a loop transmission path and a synchronization station exchanges information via the loop transmission path by transmitting frames, there is a synchronization slot that synchronizes each data station and a synchronization slot that synchronizes the information. an address slot that specifies the device to be received; a first data slot that is uniquely assigned to each data device and that transmits a block of information; and a first data slot that is uniquely assigned to each sensor base and that transmits a block of information. a second data slot for serially transmitting a second data slot, and a synchronization station that inserts the same address as that of the frame into the address slot of the next frame and transmits the data. Transmission method.