How to save the previous run data?,
i'm using AC500 PM583-eth plc. i have a problem that is if i turn off and turn on the plc the previous data is getting erased. how to solve this issue.
In case you need retain value, I could recommend using of named variables for it and analog input value, instead of %MW format. Use %MW format only if you need to exchange that variables to other PLC/HMI trough Modbus.
Then declare the variable SETPOINT (named format example) as RETAIN PERSISTENT as in example below. You can also put initial value e.g. 200 for it, for having some value at it during first download of the logic to the CPU.
For making %MW variables retain, you have to use %RB area of the PLC and create logic to transfer your variables to it - first cycle from %RB to %MW, otherwise from %MW to %RB.