Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 150)

Timers and Counters
Chapter 11
11-5
When the rung condition becomes:
True
Timer begins counting time-base intervals.
Bit 15 is set when AC=PR and the timer stops timing.
Bit 17 is set.
False
Accumulated value is retained.
Bit 15 - no action is taken.
Bit 17 is reset.
Important: The RTO instruction retains its AC value when the:
Rung condition turns false.
Processor changes to remote/program mode.
Power outage occurs and memory backup is maintained.
The Retentive Timer Reset instruction resets the accumulated value and
timed bit of the retentive timer to zero. This instruction is given the same
word address as its corresponding RTO instruction. When the rung
conditions go true, the RTR instruction resets the AC value and resets the
status bits to zero.
010
00
RTR
030
PR 150
AC 000
When the rung condition becomes:
True
RTR instruction resets the accumulated value of the RTO instruction.
Bits 15 and 17 are reset.
False
No action is taken.
Retentive Timer Reset