Set Value Specification Method; Cautions On Use; Details Of Timer Operations And Timer Accuracy - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
2.5.3

Set value specification method

1. Specification using a constant (K)
X003
2. Indirect specification using a data register
X001
X003
2.5.4

Cautions on use

1) Use timers T192 to T199 in subroutines and interrupt routines. These timers execute counting when a coil
instruction or END instruction is executed.
Once the count value of such a timer has reached the set value, the timer output contact turns ON when
a coil instruction or END instruction is executed.
Because general type timers execute counting only when a coil instruction is executed (refer to "2.5.5
Details of timer operations and timer accuracy" below), they do not operate normally if they are used in
subroutines or interrupt routines in which a coil instruction is executed only in a certain condition.
2) If a retentive type timer for 1 ms pulses is used in a subroutine or interrupt routine, its output contact turns
ON when the first coil instruction is executed after its count value has reached the set value.
3) For writing the symbolic information and changing the set values of timers and counters using a
peripheral equipment, it is recommended to create programs with the set values specified indirectly.
If the set values are specified directly, programs cannot be restored from the symbolic information after
the set values are changed.
2.5.5

Details of timer operations and timer accuracy

A timer (except interrupt execution type) starts counting when the coil is driven, and its output contact turns
ON when the first coil instruction is executed after the timer has reached timeout.
X010
TS0
52
OUT_T
EN ENO
TCoil
TC10
K100
TValue
Constant (decimal integer)
10-sec timer
MOV
EN ENO
s d
K100 D5
OUT_T
EN ENO
TCoil
TC10
D5
TValue
D5=K100
10-sec timer
Input processing
OUT_T
EN ENO
Timer starts counting.
TCoil
TC0
K12
TValue
Y010
T10 is a timer for 100 ms (0.1 s) pulses.
When the constant "100" is specified, T10 works as a
10-second timer (0.1 sec × 100 = 10 sec).
Write in advance a value to the data register used for
indirect specification in a program, or set such a value in
advance using a digital switch.
Note that the set value of a latched (backed-up) type
register can be indefinite when the battery voltage
becomes low.
Counting operation (If the operation cycle is long,
it automatically counts two or more clocks.)
X010=OFF ON
1st cycle 2nd cycle
2 Devices in Detail
2.5 Timer [T]
Contact is not
activated at this point.
T 0
Contact is
1.2
activated.
sec
timeout
Y010
ON
"n"th cycle "n+1"th cycle