Modbus Exception Response Code of 08 Memory Parity Error

[BobO]

That all looks fine. Mostly that just allows me to see the system initialization, but I wanted to make sure there was nothing weird there.

$DebugTrapAddr (DST411) might also shed light.

[eman5oh]

DST411 shows ? in the data view window, how do you properly view the contents? The PLC rebooted itself twice over the weekend as well DST400-DST409 now is full of the same pattern repeating 806 followed by 1075183616 repeating 5 times now.

[BobO]

DST411 can show the address that caused an exception. The value may or may not be useful depending on what happened. If it is constantly the same value, that can indicate a specific firmware bug and can be very useful. If it is a different value, or not set at all, that could point to a random failure like noise or some kind of comm fault.

There are other diagnostics we can do, but they require custom firmware builds. It may be prudent to continue this discussion via email. Give us a shout at support@hosteng.com.