Write limit on retain area and %RB on AC500-Eco?
Is there a limit to how often i can write to the retain area and %RB area on the AC500-Eco PLC?
As far as I can find out it is based around flash memory and ususally flash have a write limit.
Is it for example ok to use it for variables that change many times per second?
Will it wear out the flash memory or is it in ram and writes down when you get a power loss?
In this case it is a PM564
- VAR_RETAIN data
1 kB, always buffered in flash
- %RB data (persistent)
1 kB, can be buffered in flash (depending on configuration)
As I know, there is no limitation on how fast or how many times you write to retain vaules, at least I didn't find that.
Anyhow, I can agree to write to this variable at some longer period, not a few times per second. In case of power failure it is not clear when is the last saved value. Normally I put setpoints and adjustable variables in retain variables.