Disabling data backup during a warm start

PauloBalbino · ‎2023-01-31

I would like to know how to disable data backup (memory persistence) on a warm start on a M221 PLC using Machine Expert Basic as programming software. In other PLCs like Allen Bradley/Rockwell or Siemens you have the option to select which symbols/memory area you want to persist.

What is currently happening:

Both %M and %MW registers are being saved, so when PLC loses power and gets power back, it restores the values.

What is my expectation:

Be able to control which symbols/memory area is going to be persisted or not.

Current workaround:

On the ladder in case I detect on the first scan a Warm start I trigger (force) a Cold start (%S0 to 1)

Is this possible on this PLC/Software?

Bastian_Schmitz · ‎2023-01-31

Hello,

Yes you could reinitial the values with %S0. If you did not want to have these values persistent use an other memory space. the first 50 words are peristent per default. If you use word in a higher memory range these words are not longer persistent.

See Answer In Context

Bastian_Schmitz · ‎2023-01-31

Hello,

Yes you could reinitial the values with %S0. If you did not want to have these values persistent use an other memory space. the first 50 words are peristent per default. If you use word in a higher memory range these words are not longer persistent.