Internal Clock [M8011 To M8014]; Real Time Clock [M8015 To M8019 And D8013 To D8019] - Mitsubishi Electric MELSEC FX3U Programming Manual

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

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)

37.2.7 Real time clock [M8015 to M8019 and D8013 to D8019]

1. Assignment of special auxiliary relays (M8015 to M8019) and special data registers (D8013
to D8019)
Number
M8015 Clock stop and preset
Time
M8016
stopped
M8017 ±30 seconds correction
M8018 Installation detection
Real time clock (RTC)
M8019
error
Number
D8013
D8014
D8015
D8016
D8017
D8018
D8019 Day-of-the-week data
912
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
Name
When M8015 turns ON, the real time clock is stopped.
At the edge from ON to OFF, the time from D8013 to D8019 is written to the PLC
and the clock is started again.
read display is
When M8016 turns ON, the time display is stopped (but RTC is continued).
At the edge from OFF to ON, the RTC is set to the nearest minute.
(When the second data is from 0 to 29, it is set to 0. When the second data is from
30 to 59, it is set to 0 and the minute data is incriminated by "1".)
This device is always ON.
When the data stored in special data registers is outside the allowable time, setting
range this device turns ON.
Name Set value range
Second data
Minute data
Hour data
Day data
Month data
Year data
(last two digits of year)
(which corresponds to
Sunday to Saturday)
→ For the real time clock setting method, refer to Subsection 37.2.8.
37 Operation of Special Devices (M8000 -, D8000 -)
37.2 Supplement of Special Devices (M8000 - and D8000 -)
Operation and function
0 to 59
0 to 59
Use these devices for writing the initial value in time setting
or read the present time.
0 to 23
1 to 31
• D8018 (year data) can be changed over to the four-digit
1 to 12
year mode.
In the four-digit year mode, 1980 to 2079 can be
00 to 99
displayed.
• Clock accuracy: ±45 sec/month (at 25°C)
0 to 6
• Leap year correction: Provided
Operation and function