ABB encoder board LDGRB-01 position detection module LD GRB-01 products are widely used in: electric power, petroleum, mine lifting, port, heating, gas, water supply, sewage treatment, metallurgy, paper making, textile, chemical, water conservancy and other modern industrial fields!
1,Power Plant DCS Monitoring System
2, "Intelligent flat tempering furnace system manufacturing
3,PLC Programmable Conveyor Control System
4, "DCS centralized control system
5,Intelligent Fire Fighting Water Supply Control System
6,Constant flow computer control system for chemical plant chemicals
7,Electrical control system" paper making, printing and dyeing production line, substation integrated automation control system
Keywords: PLC programmable control system, decentralized control system (DCS) safety instrumentation system (SIS), ESD system, vibration monitoring system, turbine control, compressor control system (CCS) and other types of industrial control system components.
ABB encoder board LDGRB-01 position detection module LD GRB-01
The communication process uses Bland C to write the communication program between the host and the PLC.
Firstly, the COM1 port must be initialized with a baud rate of 9600bps, parity bits with even parity, and seven valid data bits. The initialization detection process of communication is shown in Figure 4. When the computer receives the answer character ACK from the PLC, it can enter the data communication. The timing diagram of communication is shown in Figure 5.
The computer can read, write and force ON/OFF operation for each soft device in the PLC. In addition to the PLC timer and counter settings using constant values, as well as the data in the file registers, all the switch inputs and outputs of the FX2 series PLC and each software device is transparent to the computer. The format of the multi-character frame during operation is shown in Figure 3. However, different operations differ in the "multiple characters" item. For example, the computer to read the PLC's soft device Y20 to Y37 operation, check the device address table for 00A2, read 2 bytes of data.
Its status is shown in Figure 6 (a), the format of the command issued by the host as shown in Figure 6 (b), the information returned by the PLC as shown in Figure 6 (c).
If there is an error in the transmitted command, the PLC returns the NAK signal and this operation fails and is performed again.
In order to ensure accurate communication between the host computer and PLC, the host computer must also be summed and calibrated according to the communication protocol.
If there is an error in the received information, read it again. If repeat 3 times still can not, then display the error message. The above programming is easily achieved using C language.
