User`s manual

3 - 5 3 - 5
MELSEC-Q
3 DATA USED FOR PROCESS CONTROL INSTRUCTIONS AND HOW TO
SPECIFY DATA
(3) Loop tag past value memory
(a) The loop tag past value memory is an area used by the QnPHCPU system at the time of
process control instruction execution.
The user cannot write data to this memory during run.
If the user writes data to the loop tag past value memory during run, normal operation
cannot be performed.
(b) The loop tag past value memory is a 32-word area after the loop tag memory.
(c) At the start of the process control instruction, write "0" to the loop tag past value memory.
3.3.2 Input data
(1) Input data is variable data given to each process control instruction.
(2) The input data uses the block word of the block memory that stores the operation result of the
process control instruction executed previously.
Process control instruction
S.IN
Input data Block word
Block bit
Process control instruction
S.PHPL
Input data
Operation result
Operation result
Transferred by user
Block memory*
Block word
Block bit
(3) The application of the input data changes depending on the used instruction. Refer to the
explanation section of the corresponding instruction.
REMARKS
*: Refer to Section 3.3.3 for the block memory.