HONEYWELL FC-QPP-0002 Measurement Control Device

FC-QPP-0002 is the processing of cable switching time. Because the PC/PPI cable is used, the cable switching time should be considered in the user program of the S7-200 CPU. the delay time between the S7-200 CPU receiving the request message from the RS232 device and its sending the response message must be greater than or equal to the cable switching time. the baud rate is 9600bps and 19200bps, the cable switching time is 2ms and 1ms, respectively. The baud rate is 9600bps and 19200bps, the cable switching time is 2ms and 1ms respectively. in the ladder program can be timed interrupt to achieve the switching delay.

FC-QPP-0002 is the handling of communication reliability, the use of check digit is one of the most commonly used measures to improve communication reliability. Used more is different or check, that is, the first character in each frame (excluding the starting character) to the last character in the body of the frame for the different or operation, and the result of the different or (exhibit or check code) as part of the message sent to the receiver. The receiver receives the data and calculates the exhibit or check code of the received data, and then compares it with the check code transmitted by the sender, and if it is different, it can be judged that there is an error in communication.