Appendix 2 Special Relay List - Mitsubishi Q2ACPU User Manual

APPENDICES

APPENDIX 2 Special Relay List

Special relays, SM, are internal relays whose applications are fixed in the PLC.
For this reason, they cannot be used by sequence programs in the same way as the
normal internal relays.
However, they can be turned ON or OFF as needed in order to control the CPU module
and remote I/O modules.
The heading descriptions in the following special relay lists are shown in Table App. 2.1.
Item
Number • Indicates special register number
Name • Indicates name of special register
Meaning • Indicates contents of special register
Explanation • Discusses contents of special register in more detail
• Indicates whether the relay is set by the system or user, and, if it is set by the system, when setting is performed.
<Set by>
S
U
S/U
<When set>
Indicated only for registers set by system
Set by
Each END
(When set)
Initial
Status change
Error
Instruction execution : Set when instruction is executed
Request
System switching
• Indicates the corresponding special relay (M9
Corresponding
(When the contents are changed, the special relay is represented M9
ACPU M9
• New indicates the special relay newly added to the QnACPU.
Indicates the corresponding CPU module type name.
Corresponding
QnA
CPU
Each CPU module model name: Indicates the relevant specific CPU module. (Example: Q4AR, Q2AS)
For details on the following items, refer to the following manuals:
Table App. 2.1. Explanation of special relay list
: Set by system
: Set by user (sequence programs or test operations from GX Developer)
: Set by both system and user
: Set during each END processing
: Set only during initial processing (when power supply is turned ON, or when going from STOP
to RUN)
: Set only when there is a change in status
: Set when error occurs
: Set only when there is a user request (through SM, etc.)
: Set when system switching is executed.
: Indicates the QnA series and Q2ASCPU series.
• Networks Manual of the corresponding network module
• SFC QCPU(Q mode)/QnACPU Programming Manual (SFC)
Function of Item
) of the ACPU.
App - 48
format change.)