Table of Contents
Advertisement
3 DATA USED FOR PROCESS CONTROL INSTRUCTIONS AND HOW TO
SPECIFY DATA
3.3 Data Used for Process Control Instructions
The following data are used for the process control instructions.
• Loop tag memory
• Input data
• Block memory
• Operation constant
• Local work memory
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 QnPHCPU/
QnPRHCPU 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.
Specified device
(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 Section 2.3.
(b) The loop tag memory consists of 96 words.
(c) Refer to Appendix 2 (Loop tag memory list) for the applications of the area used by the
process control instructions in the loop tag memory.
3 - 4
Section 3.3.1
Section 3.3.2
Section 3.3.3
Section 3.3.4
Section 3.2
Loop memory
+0
Loop tag memory
+95
+96
Loop tag past value memory
(Usage possible on the user's
side.)
+127
96word
32word
MELSEC-Q
3 - 4
Advertisement
Table of Contents
