LadderLogic
Member
Guys:
It's been a very long while since I worked with an SLC500 PLC so my question is for those of you who are current. This morning I encountered a strange problem I cannot seem to find a fix for.
A PLC with 5/05 CPU (firware rel. OS10, I beleive) would not switch to "Run" mode upon power-up although the keyswitch is in "Run" position and the program and the data are valid and the Ethrenet communications work.
When looking into the processor status with RSLogix, there are no faults and the CPU is in "Download" mode (???). The only way to reset this condition is to flip the keyswitch into "Prog" and then back to "Run" - after which everything works just fine.
I tried cycling the power several times, and every time it was precisely the same.
Is there a setting that controls how the CPU would power-up? Or is this some strange bug? I was not able to find any information on the web yet so maybe someone knows.
Thanks in advance.
It's been a very long while since I worked with an SLC500 PLC so my question is for those of you who are current. This morning I encountered a strange problem I cannot seem to find a fix for.
A PLC with 5/05 CPU (firware rel. OS10, I beleive) would not switch to "Run" mode upon power-up although the keyswitch is in "Run" position and the program and the data are valid and the Ethrenet communications work.
When looking into the processor status with RSLogix, there are no faults and the CPU is in "Download" mode (???). The only way to reset this condition is to flip the keyswitch into "Prog" and then back to "Run" - after which everything works just fine.
I tried cycling the power several times, and every time it was precisely the same.
Is there a setting that controls how the CPU would power-up? Or is this some strange bug? I was not able to find any information on the web yet so maybe someone knows.
Thanks in advance.