Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 1254

Block Programming Instructions
Description
Flags
Precautions
1214
TMHW(815)/TMHWX(817) creates an ON-delay countdown timer (10-ms
timer set in SV) between execution of the block program instruction preceding
it and the instructions following. TMHW(815) can time from 0 to 99.99 s with a
timer accuracy of 0 to 0.01 s. TMHWX(817) can time from 0 to 655.35 s with a
timer accuracy of 0 to 0.01 s.
Note The timer accuracy for CS1D CPU Units is 10 ms + the cycle time.
The first part of the block program is executed the first time the block program
is entered. When TMHW(815)/TMHWX(817) is reached, the Completion Flag
is reset to OFF, the timer is preset to the SV, and execution of the rest of the
block program will wait until SV has expired.
While the timer is timing down, only TMHW(815)/TMHWX(817) will be exe-
cuted to update the timer. When the timer times out, the Completion Flag will
turn ON and the rest of the block program will be executed. Once the entire
block program has been executed, the process will be repeated.
TMHW(815)/TMHWX(817) can be thought of as a WAIT instruction with a
timer for the execution condition and it can thus be used for timed step pro-
gressions.
Name
Error Flag
The rest of the block program following TMHW(815)/TMHWX(817) will be exe-
cuted if the Completion Flag for the timer is force set.
If the Completion Flag for the timer is force reset, the only TMHW(815)/
TMHWX(817) will be executed in the block program until the force reset status
is cleared.
The present value of timers programmed with timer numbers 0000 to 2047 will
be updated even when the timer is on standby. The present value of timers
programmed with timer numbers 2048 to 4095 will be held when the timer is
on standby.
The timer numbers are also used by the other timer instructions. Operation
will not be predictable if the same timer number is used for more than one
timer instruction. Use each timer number only once. The only way that the
same timer number can be used dependably is if only one of the timers is ever
"A"
executed.
SV preset.
Label
ER ON if TMHW(815)/TMHWX(817) is not in a block pro-
gram.
ON if an indirect IR designation is used for N in BCD
mode and the address is not for a timer present value.
ON if in BCD mode and SV is not BCD.
OFF in all other cases.
Section 3-32
Time elapsed.
"B" executed.
"C" executed.
Operation