Dziadek

Before that everything worked fine, I could upload or download program, set plc state to run, program, etc. Cable that worked wit it I bought with cpu unit. Today I tried with one that I prepared basing on "operational manual", still nothing. With protocol.. it was because I wanted to check something, I don't remember even what it had to be. Pin 8 was on during tries with protocol, now it's off. With 5 I have to try, maybe it will work.

Hello, First thing, I'm new over here, so probably I don't know everything, and second thing, sorry if my English is worse than I think :( Now, what's the problem: I have CQM1H - CPU51 plc, and until yesterday it worked fine. But when I tried to look into its communication protocols via cx-protocol, something went wrong as I suppose. Since that, I'm unable to connect to plc - usually message is "Failed to connect, check following:..." or sometimes "No response from plc" (which probably means that there is connection if pc can send data to plc?). LED "comm" on plc is not blinking when I'm trying to connect, so it looks... not good for me. I tried using rs232 port in cpu unit, on serial communications board, only peripheral left, because I don't have matching cable. Anybody knows how to make communication work again?