145
Precautions The PVs of totalizing timers in interlocked program sections are maintained
when the execution condition for IL(02) is OFF. Unlike timers and high-speed
timers, totalizing timers in jumped program sections do not continue timing, but
maintain the PV.
Power interruptions will reset timers.
Totalizing timers will not restart after timing out unless the PV is changed to a
value below the SV or the reset input is turned ON.
A delay of one cycle is sometimes required for a Completion Flag to be turned
ON after the timer times out.
The SV of the timers can be set in the range #0000 to #9999 (BCD). If the SV for a
timer is set to #0000 or #0001, it will operate in the following way. If the SV is set
to #0000, when the timer input goes from OFF to ON, the Completion Flag will
turn ON. If the SV is set to #0001, because the timer accuracy is 0 to –0.1 s, the
actual time will be a value between 0 and 0.1 s, and the Completion Flag may
turn ON as soon as the timer input goes from OFF to ON. With other values also,
allow for a timer accuracy of 0 to –0.1 s when setting the SV.
Flags ER (SR 25503):Content of ∗DM word is not BCD when set for BCD.
SV is not BCD.
Example The following figure illustrates the relationship between the execution conditions
for a totalizing timer with a set value of 2 s, its PV, and the Completion Flag.
Address Instruction Operands
00000 LD 00000
00001 TTIM(87)
TIM 000
# 0020
LR 2100
00000
TTIM(87)
TIM 000
#0020
LR 2100
Timer input
(I: IR 00000)
Reset bit
(RB: LR 2100)
Completion Flag
(TIM 000)
Present value: 0020
0000
5-14-4 COUNTER – CNT
N: TC number
# (000 through 511)
Ladder Symbol
Definer Values
SV: Set value (word, BCD)
IR, AR, DM, HR, LR, #
Operand Data Areas
CP
R
CNT N
SV
Timer and Counter Instructions Section 5-14