Omron SYSMAC CVM1 Series Operation Manual page 148

Timer and Counter Instructions
Differences in CVM1D and
C/CVM1/CV-series PCs
1, 2, 3...
Precautions
Flags
Examples
130
The following figure illustrates the relationship between the execution condition
for TIM and the Completion Flag assigned to it.
Execution condition
Completion Flag
Operation of the TIM instruction is the same in CVM1D and C/CVM1/CV-series
PCs except for the timer precision and PV refreshing in jumped program sec-
tions.
1. Timer Precision
TIMER instruction errors can be one cycle time or more (up to two cycle
times). The error range is ± (10 ms + cycle time).
2. Operation of the TIMER Instruction between JMP(004) and JME(005)
• The timer PV is refreshed every cycle during program execution.
• The timer operates normally while the execution condition of JMP(004) is
ON.
• The timer PV is not refreshed while the timer is jumped (while the execu-
tion condition of JMP(004) is OFF.)
If the timer is jumped after it has started timing, the timer count will contin-
ue decrementing but the PV will not be refreshed.
Be sure to consider the effects of the JMP(004)/JME(005) instructions on
timer PVs when using the timer PVs as data in the program.
• The Completion Flag will not be turned ON while a timer is jumped, even if
the SV elapses.
• When the execution condition for JMP(004) is changed to ON, an timer
that had been operating will continue timing down from the full time that
elapsed since the timer's execution condition went ON. If the SV elapsed
while the timer was jumped, the timer's Completion Flag will be turned ON
when the execution condition for JMP(004) is turned ON again.
SV must be between 000.0 and 999.9 and must be BCD. The decimal point is not
entered.
Each timer number can be used to define only one timer instruction unless the
timers are never active simultaneously. The TIM, TIMH(015), and TTIM(120)
timers all use timer numbers.
Power interruptions reset timers. If a timer that is not reset by power interrup-
tions is required, Auxiliary Area clock pulse bits can be counted to produce tim-
ers using CNT. Refer to 5-13-6 COUNTER: CNT for details.
If the IOM Hold Bit and PC Setup are set to retain IOM (which includes timer PVs
and Completion Flags), the timer must be reset before starting it to prevent pos-
sible malfunctions.
If you convert a TIM instruction to a TIMH(015) instruction (or vice versa) using
online programming operations, always reset the instruction's Completion Flag.
Proper operation will not be possible unless the Completion Flag is reset.
Note: Refer to page 101 for general precautions on operand data areas.
Content of *DM word is not BCD when set for BCD.
ER (A50003):
Content of S (SV) is not BCD.
All of the following examples use OUT in diagrams that would generally be used
to control output bits in the I/O Area. These diagrams can be modified to control
execution of other instructions.
ON
OFF
ON
OFF
SV
Section 5-13
SV