Internal clock on SLC 503 resetting!

[Rebuke 0]

For some reason a 503 cpu keeps resetting back to 00:00 hours even after I correct the S time files. I can't find anything that moves data to these files, and it is creating havoc with our label date codes. I'd appreciate any input

[mgvol 0]

Man, that is a strange one. If the CPU is deemed healthy and the problem persists, there is a software package Rockwell sells that will synchronize from 1 to 100 SLC/PLC5/Logix CPU's with a PC clock, at periodic intervals that you can set up. It's called CHRONOS; they don't advertise it and you have to call RA Tech support (Mary Beth Peters) to get the apllication form and pricing. It ususally ranges from $318.00 for a single CPU up to $1000.00 for 100 CPU's. You ahve to ask for her, because not everyone in Rockwell has even heard of this product (which makes it very interesting when she is on vacation, I can assure you). I will continue looking for a possible cause for your current situation. If you find a cause/solution before anyone else does, let us know.

[mgvol 0]

Is this 5/03 part of a network using RSSQL? If so, check this document and check the applicable strings in the RSSQL app. http://domino.automation.rockwell.com/appl...24?OpenDocument

[mgvol 0]

1) Are you using an EEPROM? 2) If so, is the CPU set to load from EEPROM on power-up (or power-loss)? 3) If the answer to 1 and 2 is yes, have there been any known power line disturbances (outagees, dips, etc.) around the times of the clock zeroing itself? 4) If yes to all of the above, I wonder if the CPU clock was 00:00 at the time the EEPROM was burned? I am really grasping here, as this is a strange one. It may be as simple as a CPU gone "batty".

[Snerkel 0]

Do you have a Panelview or similar system connected too the SLC, if for instance a Panelview is used to directly set the PLC clock this can cause problems when the power is cycled.