Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 245)

Chapter 17
Timer and Counter Instructions
17–13
Reset RES Output Instruction
(RES) HHT Ladder Displays:
HHT Zoom Displays:
Ladder Diagrams and APS Displays:
F1 F2 F3 F4 F5
ZOOM on RES –(RES)– 2.3.0.0.2
NAME: RESET
COUNTER: C5:0
EDT_DAT
(RES)
C5:0
(online monitor mode)
You use a reset instruction to reset timing and counting instructions. The
RES instruction can also be used to reset the position value and status bits
(except FD) of a control file (R6:0) used in sequencers, shift registers, etc.
Using the RES instruction with timers and counters: When the RES
instruction is enabled, it resets the retentive on-delay timer, count up, or
count down instruction having the same address as the RES instruction.
•
With timers, the RES instruction resets the accumulated value, done bit,
timing bit, and enable bit.
•
With counters, the RES instruction resets the accumulated value, overflow
or underflow bit, done bit, and enable bits.
If the counter rung is enabled, the CU or CD bit will be reset as long as the
RES instruction is enabled.
If the counter preset value is negative, the RES instruction sets the
accumulated value to zero. This in turn causes the done bit to be set by a
count down or count up instruction.
!
ATTENTION: Because the RES instruction resets the
accumulated value, and the done, timing, and enabled bits, do not
use the RES instruction to reset a TOF instruction. Unpredictable
machine operation or injury to personnel may occur.
Reset (RES)