· Counts time base intervals when the instruction is true and retains the accumulated value when the instruction goes false or when power cycle occurs.
· The Retentive Timer instruction is a retentive instruction that begins to count time base intervals when rung conditions become true.
· The Retentive Timer instruction retains its accumulated value when any of the following occurs:
· Rung conditions become false.
· Changing Processor mode from REM run /Test / program mode.
· The processor loses power while battery back up is still maintained.and a fault occurs.
Note:To reset the accumulated value in RTO, you must use a reset instruction (RES) with the same address.