I've encountered a weird problem backing up my old FX1N-24MR-ES/UL PLCs. Hope I can get some helps here. I'm grateful for all the help.
I got some old FX1N-24MR-ES/UL PLCs working on machines, and most of them are working 24/7 for more than 8 years now.
There's a computer in machines communicating with PLC via SC-09 harness( RS232 - RS422 ).
Since Mitsubishi isn't selling and manufacturing FX1N-24MR-ES/UL anymore, I tried to find some compatible alternatives.
I bought a Shihlin Electric AX1N-24MR-ES(It got licensed from Mitsubishi to approve it's 100% compatible with FX1N-24MR-ES/UL) and a copied FX1N-24MR-ES/UL from China.
I downloaded and verified programs/parameters into both PLCs via GX Works2(both PLCs shown as Mitsubishi FX1N-24MR in GX Works2), but they both work about 5~10% differently from the original ones on the machines. But it seems the both new PLCs are working identically.
I've tried download the original program/parameters to a old original FX1N-24MR-ES/UL and it works well, so it seems the program/parameters I read out is correct.
I've also checked the both VRs(D8030, D8031) aren't used in the program.
May you please let me know what else I can do or test to make the new PLCs I working 100% identically as the old ones?
I'm grateful for all your kindly help guys.
Thank you and have a nice day