CJ1 - can't reset RS232 port

[pro17 0]

Hi, I use RS232 port to communicate with Modbus slave. Sometimes I get Port error flag (A392.04) and I would like to reset port with output A526.00. This doesn't work. I need to set PLC to programm mode and back to monitor mode to reset port. Has anyone experience on this matter? best regards, JinX

[Mendon Systems 22]

I have used A526.00 to reset the serial port is several programs without any problems. Possibly this is some sort of timing issue??

[pro17 0]

I can confirm this behaviour is normal. The problem is that some Function Blocks use this restart bit (output is programmed in FB). If FB is locked you don't have access to source code and can't erase this in it. I was using Modbus_CPU function blocks for all functions Fn01,02,03,04, 06, and 15. Every one of FB's had restart bit in it. I erased them and used restart bit only in my main program, which works perfectly. Best regards, Gregor Edited 23 Oct 2012 by pro17