Power Failure Detection Time [D8008, M8008 And M8007]; Scan Time (Monitor) [D8010 To D8012]; Internal Clock [M8011 To M8014] - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
37.2.4

Power failure detection time [D8008, M8008 and M8007]

1. FX PLC (AC power supply type)
3U
The table below shows the allowable momentary power failure time in FX
Supply voltage
100V AC system
200V AC system
2. FX /FX PLC (DC power supply type)
3U 3UC
The allowable momentary power failure time in the FX
overwrite the power failure detection time in device D8008.
DC power supply
M8000:RUN monitor
M8007:Momentary
power failure
detection
M8008:Power failure
detected
37.2.5

Scan time (monitor) [D8010 to D8012]

The present value, minimum value and maximum value of the PLC scan time (operation time) are stored in D8010,
D8011 and D8012 respectively (in 0.1-ms units).
When using the constant scan mode, the values stored in these devices include the waiting time for the constant scan
time.
D8010: Present value
D8011: Minimum value
D8012: Maximum value
37.2.6

Internal clock [M8011 to M8014]

The PLC has the following four types of internal clocks which are always oscillating while the PLC power is ON.
10ms
M8011
(10ms) 100ms
M8012
(100ms)
M8013
(1 sec)
M8014
(60 sec)
858
Allowable momentary power
failure time
10 ms
Setting range: 10 to 100 ms
Set a value to D8008.
Default: 10 ms
Approx. 2 ms
1 scan time
D8008
Power failure detection time
5ms
The values stored in these devices can be
monitored from peripheral equipment.
100Hz
Caution:
Even while the PLC is in the STOP mode, these clocks are always
oscillating. Therefore, the rising edge of the RUN monitor (M8000)
10Hz
does not synchronize with the clock start timing.
1Hz
1s
1min
37 Operation of Special Devices (M8000 -, D8000 -)
37.2 Supplement of Special Devices (M8000 - and D8000 -)
PLCs (AC power supply type).
3U
AC power supply
M8000: RUN monitor
M8007: Momentary
power failure
detection
M8008: Power failure
detected
/FX PLCs (DC power supply type) is 5 ms. Do not
3U 3UC
Approx. 5 ms
1 scan time
D8008
Power failure
detection time
10ms