Appendix 3 List Of Special Register Areas - Mitsubishi Electric Q26UD(E)HCPU User Manual

Appendix 3
The special register (SD) is an internal register whose application is fixed in the programmable controller. For this
reason, the special register cannot be used in the same way as other internal registers are used in sequence
programs. However, data can be written to the special register to control the CPU module as needed. Data is stored in
binary format if not specified.
The following table shows how to read the special register list.
Item
Number Special register number
Name Special register name
Meaning Contents of special register
Explanation Detailed description of special register
Set side and set timing of special register
<Set by>
• S: Set by system
• U: Set by user (using a program, programming tool, GOT, or test operation from other external devices)
• S/U: Set by both system and user
<When Set>
The following shows the set timing when the special register is set by system.
• Every END processing: Set during every END processing
• Initial: Set during initial processing (after power-on or status change from STOP to RUN)
Set by (When Set) • Status change: Set when the operating status is changed
• Error: Set if an error occurs
• Instruction execution: Set when an instruction is executed
• Request: Set when requested by a user (using the special relay)
• When condition occurs: Set when the condition is triggered
• When system is switched: Set when the system is switched (between the control system and the standby system)
• When RUN/STOP/RESET switch changed: Set when the RUN/STOP/RESET switch is changed
• Card removal: Set when a memory card is inserted or removed
• At write: Set when data are written to the CPU module by a user
• During END processing: Set during END processing
CPU module supporting the special register
• QCPU: All the Q series CPU modules
• Q00J/Q00/Q01: Basic model QCPU
• Qn(H): High Performance model QCPU
• QnPH: Process CPU
Corresponding CPU • QnPRH: Redundant CPU
• QnU: Universal model QCPU
• QnUDV: High-speed Universal model QCPU
• Q00UJ/Q00U/Q01U: Q00UJCPU, Q00UCPU, and Q01UCPU
• LCPU: All the L series CPU modules
• CPU module model: Only the specified model (Example: Q02UCPU, L26CPU-BT)
Corresponding • Special register (D9) supported by the ACPU ("D9 format change" indicates the one whose application has been
ACPU changed. Incompatible with the Q00J/Q00/Q01 and QnPRH.)
D9 • "New" indicates the one added for the QCPU or LCPU.
For details on the following items, refer to the following.
• For network related items:  Manuals for each network module
• For SFC programs:  MELSEC-Q/L/QnA Programming Manual (SFC)
Do not change the values of special register set by system using a program or by test operation. Doing so may result in
system down or communication failure.
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List of Special Register Areas
Description