Chapter 6 Applied Instructions character is received, the period of time is measured. Whenever a character is received, the measured time is cleared to 0. The instruction generates the communication timeout flag if the time measured is greater than the communication timeout setting value. When receiving of data is complete, the instruction sets the completion flag. You must clear the flag before receiving more data. The instruction is stopped for one cycle after the completion flag is set. Then the instruction can be started in the next cycle. 5. There is no limit to the number of times the instruction can be executed.
The instruction can use only one communication port for the output and execution of one communication instruction each time. If receiving and sending data is complete, you must disable the instruction to correctly release the communication control. 6. The instruction cannot be used in the ST programming language, interrupt tasks or function block which is called only once. Example of setting the communication protocol 1. Set the PLC COM1 (RS485) port with station address 2 and the communication format in HWCONFIG with these values: ASCII , 115200, 7, N, 2. 2. Set the motor drive parameters using the panel on the Delta C2000 AC motor drive according to the following steps. A. Set 09-00 to 1:
the station address of the AC motor drive is set to 1. 6_ B. Set 09-01 to 115.2: RS485 baud rate of the AC motor drive is 115200. C. Set 09-04 to 1: RS485 communication format of the AC motor drive is 7, N, 2. D. Set 09-20 to 1: the frequency instruction is input through RS485. E. Set 09-21 to 2: the running instruction is input through RS485. 6-569