How do i avoid writing in to fieldbus volatile memory? i often get error while downloading the my pid block
In reply to bobgally:
Maybe the message refers to non-volatile memory. Is the PID inside a field device? Some field devices have limits on the number of times non-volatile memory can be written. This depends on the type of non-volatile memory used in the device. For instance EEPROM may only permit 10,000 or 100,000 wirtes while other non-volatile permit infinate number of writes. The Target Mode of the block is a non-volatile parameter, so the warning is there to ensure your logic does not inadvartantly "wear down" your non-volatile memory prematurely. For instance, if the logic writes every second the non-volatile memory could wear down in a few hours or days. Instead of writing to MODE_BLK you could consider some change to the logic to use the TRK_IN_D parameter to force a local overrisde mode (LO) that sets the output to the value on the TRK_VAL input (which could be linked from OUT or elsewehere) or you could have logic that only writes the MODE_BLK::Target parameter whenever the value has actually changed (not every cycle) assuming it does not change so often.