Clock Function - Mitsubishi Q2ACPU User Manual

10. OTHER FUNCTIONS

10.5 Clock Function

The QnACPU has a clock in the CPU module.
Since the clock data can be read in the sequence program, it can be used for time control
of the user system.
In addition, the clock data can also be used for time control to the functions performed by
the CPU module, such as the breakdown history.
Clock operation by the clock function is continued with the battery when the PLC power is
turned OFF or a instantaneous power failure lasting longer than the allowable momentary
power interruption time occurs.
(1)
(2)
POINT
The CPU module system uses the clock data for a breakdown history. When using
a CPU module, be sure to set the correct time first.
Clock data
The clock data is composed of the year, month, day, hour, minute, second, and day of
the week used by the clock element in the PLC CPU, as shown below.
Data name
Year
Month
Day
Hour
Minute
Second
Day of the week
Accuracy
The accuracy of the clock function depends on the ambient temperature, as shown
below.
Ambient Temperature
0
+25
+55
Last two digits of the year
1 to 31 (Leap year, automatic identification)
0 to 23 (24-hour system)
0
1
2
3
4
5
6
Accuracy (daily variance)
-2.3s to + 4.4s (TYP. + 1.8s)
-1.1s to + 4.4s (TYP. + 2.2s)
-9.6s to 2.7s (TYP.-2.4s)
10 - 8
Description
1 to 12
0 to 59
0 to 59
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday