Operation Of Special Devices (M8000 -, D8000 -); Special Device List (M8000 -, D8000 -); Special Auxiliary Relay (M8000 To M8511) - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition

37. Operation of Special Devices (M8000 -, D8000 -)

37.1

Special Device List (M8000 -, D8000 -)

The device numbers and functions of the special auxiliary relays (indicated as "special M" in tables) and
special data registers (indicated as "special D" in tables) are shown below.
Note that functions of certain devices vary depending on the series of the PLC.
Do not use the undefined / blank special auxiliary relays and special data registers in the sequence program
since they are occupied by the CPU.
In addition, do not activate or write to the devices with brackets on the first letter such as [M]8000 or [D]8001
in the program.
→ Refer to Section 37.2 for supplementary information on analog special adapter devices.

37.1.1 Special Auxiliary Relay (M8000 to M8511)

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
• FX
3G
ON when either M8060, M8061, M8064,
[M]8004 M8065, M8066, or M8067 is ON.
Error occurrence • FX
1S
ON when either M8060, M8061, M8063,
M8064, M8065, M8066, or M8067 is ON.
ON when battery voltage is below the value set in
[M]8005
D8006.
Battery voltage low
[M]8006 It is set when battery voltage low is detected.
Battery error latch
ON for 1 scan, when momentary power failure is
detected
[M]8007
Even if M8007 turns ON, PLC continues to RUN as
Momentary power
long as the duration of power loss is within the time
failure
period specified in D8008.
Set when momentary power failure is detected.
[M]8008 If power loss time is longer than the time period
Power failure specified in D8008, M8008 is reset and PLC is
detected switched to STOP mode.(M8000=OFF).
[M]8009 ON when 24V DC power fails in either powered
24V DC down extension unit or extension power supply unit.
Operation and function
RUN
input
M8061
Error occurrence
M8000
M8001
M8002
M8003
1 scan time
→Refer to Subsection 37.2.1.
, FX , FX
3U 3UC
,FX ,FX ,FX ,FX
1N 2N 1NC 2NC
→Refer to Subsection 37.2.3.
→Refer to Subsection 37.2.3.
→Refer to Subsection 37.2.4.
→Refer to Subsection 37.2.4.
37 Operation of Special Devices (M8000 -, D8000 -)
37.1 Special Device List (M8000 -, D8000 -)
Applicable model
Correspond
FX FX FX -ing special FX
3G 3U 3UC
device
–
–
–
–
D8004
D8005
D8006
D8007
–
D8008
– D8008
D8009
FX FX FX FX
1S 1N 2N 1NC 2NC
– – –
– – –
– – –
– – –
– – –
873
31
32
33
34
35
36
37
38
A
B