Omron SYSMAC C20P Operation Manual page 66

Timer and Counter Instructions
Precautions
Flags
Examples
Example 1:
Basic Application
Example 2:
Extended Timers
58
ON
Execution condition
OFF
ON
Completion Flag
OFF
Timers in interlocked program sections are reset when the execution condi-
tion for IL(02) is OFF. Power interruptions also reset timers. If a timer that is
not reset under these conditions is desired, SR area clock pulse bits can be
counted to produce timers using CNT. Refer to 5–11–4 Counter – CNT for
details.
Program execution will continue even if a non-BCD SV is used, but timing will
not be accurate.
ER: SV is not in BCD.
All of the following examples use OUT in diagrams that would generally be
used to control output bits in the IR area. There is no reason, however, why
these diagrams cannot be modified to control execution of other instructions.
The following example shows two timers, one set with a constant and one set
via input word 01. Here, 0200 will be turned ON 15 seconds after 0000 goes
ON and stays ON for at least 15 seconds. When 0000 goes OFF, the timer
will be reset and 0200 will be turned OFF. When 0001 goes ON, TIM 01 is
started from the SV provided through IR word 01. Bit 0201 is also turned ON
when 0001 goes ON. When the SV in 01 has expired, 0201 is turned OFF.
This bit will also be turned OFF when TIM 01 is reset, regardless of whether
or not SV has expired.
0000
TIM 00
0001
TIM 01
Timers operating longer than 999.9 seconds can be formed in two ways. One
is by programming consecutive timers, with the Completion Flag of each tim-
er used to activate the next timer. A simple example with two 900.0-second
(15-minute) timers combined to functionally form a 30-minute timer.
0000
TIM 01
TIM 02
SV
Section 5–11
SV
TIM
015.0 s
00
0200
TIM
01
01
0201
TIM
900.0 s
01
TIM
900.0 s
02
0200