Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 1090

Model Conversion Instructions
Note
Flags
Note
Precautions
FIFO Stack Read Operation (Of = 9000 to 9999 BCD)
If the leftmost digit of Of is 9, COLLC(567) will operate as a FIFO stack
instruction (FIFO stands for First-In-First-Out). In this case, the rightmost 3
digits of Of specify the size of the stack.
COLLC(567) copies the data from the oldest word recorded in the stack to D.
The source word is Bs + 1. After the data is copied, the stack pointer is decre-
mented by 1.
Data is copied from
Bs + 1.
Stack area
Bs
Bs+1
S1+
Use DISTC(566) to write stack data to the stack area.
Name Label
Error Flag ER
Equals Flag =
In C-series PLCs, the DATA COLLECT (COLL) instruction will cause the Error
Flag to go ON if the content of an indirectly addressed DM word (*DM) is not
BCD, or the DM area boundary is exceeded. COLLC(567) will not cause the
Error Flag to go ON in these cases.
Once DISTC(566) has been executed with Stack Push Operation to allocate a
stack area, always specify that same length stack area in the COLLC(567)
instructions. Operation will be unreliable if a different stack area size is speci-
fied in the COLLC(567) instructions.
Be sure that the offset or stack size specified by Of does not exceed the end
of the data area when added to Bs.
The offset data in Of must be BCD.
Stack
m
Of 9
pointer
Stack m words
data area
D
Operation
ON if the offset data in Of is not BCD.
ON if LIFO or FIFO Stack Operation is specified, but the
stack pointer data in Bs is not BCD.
ON if LIFO or FIFO Stack Operation is specified and the
stack pointer indicates a word that exceeds the stack data
area.
OFF in all other cases.
ON if the source data is 0000.
OFF in all other cases.
Section 3-33
Size of
stack area
1057