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Timer and Counter Instructions Section 3-5
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.
Flags
Precautions Timer numbers are shared by the TIM, TIMX(550), TIMH(015), TIMHX(551),
TMHH(540), TMHHX(552), TTIM(087), TTIMX(555), TIMW(813),
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.)
SV
Timer input
Timer PV
Completion
Flag
Name Label Operation
Error Flag ER 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.
Equals Flag = OFF or unchanged
Negative Flag N OFF or unchanged
Condition PV Completion Flag
Operating mode changed from RUN or
MONITOR mode to PROGRAM mode or
vice versa.
1
0000 OFF
Power supply interrupted and reset
2
0000 OFF
Execution of CNR(545)/CNRX(547), the
RESET TIMER/COUNTER instructions
3
BCD: 9999
Binary: FFFF
OFF
Operation in interlocked program section
(IL(002)–ILC(003))
Reset to SV. OFF
Operation in jumped program section
(JMP(004)–JME(005))
PV continues
decrementing.
Retains previous status.
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