Goals and Symptoms

Detected on Quantum Hot Standby CPU whatever the Unity Pro version.

- The application transfer from Primary CPU to Standby CPU never end
- It’s no more possible to upload application from Primary CPU to Unity Pro
- If the CPU memory is fragmented, Unity Pro request a memory pack (red ‘’mem’’ icon in the status bar). Doing a memory pack from Unity Pro with application corrupted will lead to a PLC stop with a stop code A100.

Facts and Changes

All these 3 Quantum CPU behaviors are linked to application corrupted.
Mainly it’s upload code block that is corrupted in CPU memory, means no risk for application code execution.

Causes and Fixes

1^st action do not proceed for a memory pack to prevent CPU stop.

How to detected this kind of corrupted application:
From Unity Pro, do an application transfer from PLC to PC.
In ucmerr.log (C:\ProgramData\Schneider Electric\Unity Pro) you will find the following messages that ended with ‘’Error in Checksum for RTE …’’

To work around this situation, you need :
1 To connect with Unity Pro to the Primary CPU and make sure application in the PC is equal with application in the PLC.
2 Disconnect from Primary & connect to the Standby PLC and load the application to CPU.
3 As applications are equal data variables are synchronizing from Primary to Standby CPU.
4 Power off the Primary CPU and the Standby is taking the lead and become new Primary.
5 If PCMCIA memory card exist in CPU remove it on the CPU that is power off, remove batteries to clear the memory (off 1 min).
6 Put back PCMCIA in old Primary and power it on by pressing the ESC button on the CPU display (keep it pressed min 5 sec) and release the button.
7 The CPU is restarting from empty and will load application and data from the new Primary CPU.
8 Make the CPU restarted in Standby mode.
You have escape from the corrupted application that was deleted from the CPU.

Released for:Schneider Electric Global