Operations Of Special Devices (M8000 And Later, D8000 And Later); Special Device List (M8000 And Later, D8000 And Later); Special Auxiliary Relays (M8000 And Later) - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
4. Operations of Special Devices (M8000 and later, D8000
and later)
4.1

Special Device List (M8000 and later, D8000 and later)

This section explains types and functions of special auxiliary relays (indicated as "special M" in tables) and
special data registers (indicated as "special D" in tables).
Note that functions of certain devices vary depending on the PLC series even if the device number is same.
Do not use undefined and blank special auxiliary relays and special data registers in sequence programs
because they are occupied by the CPU.
Do not activate or write data to devices with brackets on the first character such as "[M]8000" and "[D]8001" in
programs.
4.1.1

Special auxiliary relays (M8000 and later)

1. FX /FX /FX
3S 3G
Number and name
PLC status
[M]8000
RUN monitor
NO contact
[M]8001
RUN monitor
NC contact
[M]8002
Initial pulse
NO contact
[M]8003
Initial pulse
NC contact
[M]8004 Remains ON while either one among M8060, M8061,
Error occurrence M8064, M8065, M8066 or M8067 is ON.
[M]8005 Remains ON while the battery voltage is abnormally low.
Battery voltage low
[M]8006
Turns ON when abnormally low battery voltage is detected.
Battery voltage low
latch
Remains ON during 1 scan when instantaneous power
interruption is detected.
[M]8007
Even if M8007 turns ON, the PLC continues operation as far
Instantaneous power
as the duration of low supply voltage is within the time
interruption
period specified by D8008.
It is set when momentary power failure is detected.
When the duration of low supply voltage exceeds the time
[M]8008
period specified by D8008, M8008 turns OFF and the PLC
Power interruption
switches to the STOP mode (M8000 = OFF).
[M]8009 ON when 24 V DC power fails in any I/O extension units or
24V DC failure special function unit/block.
138
→ For supplementary information on special devices, refer to Section 4.2.
/FX /FX PLCs
3GC 3U 3UC
Operation and function
RUN
input
M8061
Error occurrence
M8000
M8001
M8002
M8003
Scan time
→ Refer to Subsection 4.2.1.
→ Refer to Subsection 4.2.3.
→ Refer to Subsection 4.2.3.
→ Refer to Subsection 4.2.4.
→ Refer to Subsection 4.2.4.

4 Operations of Special Devices (M8000 and later, D8000 and later)

4.1 Special Device List (M8000 and later, D8000 and later)
FX 3U FX 3UC
Applicable model
Corresponding
FX 3G FX 3GC FX 3S
special device
-
-
- - -
- - -
-
-
-
-
-
D8004
D8005
D8006
D8007
D8008
D8008
D8009