Mitsubishi Electric MELSEC Q Series User Manual page 190

(4) Precautions
(a) First I/O numbers of CPU modules
The following values are set for the CPU module's first I/O number in the write/read instructions.
CPU No.
Value set in the first I/O number
*1: Since the number of mountable CPU modules is three when using a Basic model QCPU, Q00UCPU, Q01UCPU,
Q02UCPU, "PLC No.4" is not selectable.
(b) Writing to CPU shared memory
Do not write data to the following areas in the CPU shared memory.
• Restricted system area
• Auto refresh area
(c) Access to module in reset status
No error will occur even if the CPU accessed with a write instruction is in reset status.
However, access execution flag (SM390)
completed.
(d) Simultaneous access to CPU module
Establish an interlock to prevent simultaneous access during interactive data communication with write/read
instructions.
Old data and new data may be mixed together if simultaneous access is carried out.(
íç1
High
Note4.10
performance
For the High Performance model QCPU or the Process CPU, reading data from "Restricted system area" and "Auto
refresh area" is not also allowed.
Note4.11
Universal
An access executing flag (SM390) is unavailable for the Universal model QCPU.
Table4.12 First I/O numbers of CPU modules
CPU No.1
Process
CHAPTER4 COMMUNICATIONS BETWEEN CPU MODULES
CPU No.2
3E0 3E1
H H
will remain OFF after the instruction execution has been
Note4.11
CPU No.3 CPU No.4
3E2 3E3
H
( Section 4.1.1)íç1
Note4.10
Section 4.1.2)
1
2
3
* 1
H
4
5
6
7
8
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