Data Used For Process Control Instructions; Loop Memory - Mitsubishi MELSEC-Q series Programming Manual

3.3

Data Used for Process Control Instructions

The following data are used for the process control instructions.
• Loop tag memory Page 27, Section 3.3.1
• Input data Page 28, Section 3.3.2
• Block memory Page 29, Section 3.3.3
• Operation constant Page 29, Section 3.3.4
• Local work memory Page 26, Section 3.2
3.3.1

Loop memory

(1) Loop memory
(a) The loop memory is an area that stores the data used commonly by the process control instructions specified as the
loop type.
The loop memory also has an area that stores the data used by the CPU module system during process control
instruction execution.
(b) The loop memory has the "loop tag memory" and "loop tag past value memory" areas.
(c) The loop memory consists of 128 words (word device: 128 points).
When setting the loop memory areas, specify the device that can occupy 128 words consecutively.
(2) Loop tag memory
(a) The loop tag memory is an area that stores the data used commonly by the process control instructions specified as
the loop type indicated in Page 22, Section 2.3.
(b) The loop tag memory consists of 96 words.
(c) Refer to Page 259, Appendix 2 (Loop tag memory list) for the applications of the area used by the process control
instructions in the loop tag memory.
Loop memory
Specified device +0
Loop tag memory
+95
+96
Loop tag past value memory
(Usage possible on the user's
side.)
+127
96word
32word
1
2
3
4
6
6
7
8
27