Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 209

Timer and Counter Instructions
Flags
Precautions
176
The following timing chart shows the behavior of the timer's PV and Comple-
tion Flag when the timer input is turned OFF before the timer times out.
Timer input
SV
Timer PV
Completion
Flag
Name Label
Error Flag ER
Equals Flag =
Negative Flag N
Timer numbers are shared by the TIM, TIMX(550), TIMH(015), TIMHX(551),
TMHH(540), TMHHX(552),
TIMWX(816), TMHW(815), and TMHWX(817) instructions. If two timers share
the same timer number, but are not used simultaneously, a duplication error
will be generated when the program is checked, but the timers will operate
normally. Timers which share the same timer number will not operate properly
if they are used simultaneously.
Timers created with timer numbers 16 to 4095 will not operate properly when
the CPU Unit cycle time exceeds 100 ms. Use timer numbers 0 to 15 when
the cycle time is longer than 100 ms.
TIMH(015)/TIMHX(551) timers created with timer numbers 0 to 15 are
refreshed every 10 ms. Use these timer numbers when the PV is being refer-
enced in the user program.
The present value of timers programmed with timer numbers 0 to 15 will be
updated even when the timer is on standby. The present value of timers pro-
grammed with timer numbers 16 to 4095 will be held when the timer is on
standby.
The operation of the = Flag and N Flag depends on the model of the CPU
Unit. Refer to Flags, above, for details.
Timers will be reset or paused in the following cases. (When a timer is reset,
its PV is reset to the SV and its Completion Flag is turned OFF.)
Condition
Operating mode changed from RUN or
MONITOR mode to PROGRAM mode or
1
vice versa.
Power supply interrupted and reset
Execution of CNR(545)/CNRX(547), the
RESET TIMER/COUNTER instructions
Operation in interlocked program section
(IL(002)–ILC(003))
Operation in jumped program section
(JMP(004)–JME(005))
Operation
ON if N is indirectly addressed through an Index Register
but the address in the Index Register is not the PV
address of a timer.
ON if in BCD mode and S does not contain BCD data.
OFF in all other cases.
OFF or unchanged
OFF or unchanged
TTIM(087), TTIMX(555),
PV
0000
2 0000
BCD: 9999
3 Binary: FFFF
Reset to SV.
PV continues
decrementing.
Section 3-5
TIMW(813),
Completion Flag
OFF
OFF
OFF
OFF
Retains previous status.