We assume that some Electrostatic discharge or other noise event disrupt the memory to load the program or there is a low battery (SB8=1). verify it on this PLC.
Please re-download the project after referring my next information how to avoid such problem in the future:
All our controllers have FLASH memory, which is non-volatile storage media . Program is kept secured and doesn’t depend on power supply or battery backup.
In Jazz, M91, V120 and V2xx series PLC the program is downloaded and burned automatically direct to FLASH.
In enhanced Vision models (V130/350/V430/560/570/1040/1210) the program is downloaded to RAM. RAM is power dependent and is battery backup.
Download to RAM has the advantage, that you can transfer only part of the program (we call it DLU – Download Unit) while edit and debug and this download is very fast.
When you wish to download a project, you can choose one the following download options:
Please note that we highly recommend to back-up the project also in SD card, then you can re-download the project to the PLC as follow: