Mitsubishi Electric Q01UCPU User Manual page 130

(4) Precautions
(a) Initial clock data setting
No clock data is set at the factory.
Clock data is required for some functions of the CPU module used in the system, such as error history data
storage, or for intelligent function modules.
Before using the CPU module for the first time, set the time correctly.
(b) Clock data correction
If clock data is corrected, rewrite all clock data to the CPU module.
(c) Clock data setting range
When changing clock data, write data within the range given in Page 125, Section 3.5 (2).
If data outside of clock range is written to the CPU module, the clock function does not operate normally.
However, the CPU module does not detect an error if the clock data is within the range.
Write operation to the CPU module
February 30
32th of month 13
(d) Use for clock data of 1/1000 sec.
• Function that clock data of 1/1000 sec. can be used
Only the following instructions can use the clock data of 1/1000 sec. Other instructions cannot use data of
1/1000 sec. (such as data read using SM/SD, data indicating error occurrence time stored as error history
data, data read using a programming tool, and data read using dedicated instructions for other modules.)
• When clock data is changed
When clock data is changed using a programming tool or instructions (including dedicated instructions for
other modules), the clock data of 1/1000 sec. is reset to 0.
(5) Clock data accuracy
Accuracy of the clock data varies depending on the ambient temperature as shown below.
(6) Clock data comparison
To compare clock data in a sequence program, read the clock data with the DATERD instruction (instruction for
reading clock data).
Since the DATERD instruction reads the year data in four digits, the data can be compared by the comparison
instruction without any modifications.
128
Executed
Not executed
• S(P).DATERD
• S(P).DATE+
• S(P).DATE-
Ambient temperature (°C)
0
+ 25
+ 55
CPU module operation
An error is not detected.
• When the DATEWR instruction is executed, "OPERATION ERROR"
(error code: 4100) is detected.
• When SM210 is on, SM211 turns on.
Accuracy (Day difference, S)
-2.96 to +3.74 (TYP.+1.42)
-3.18 to +3.74 (TYP.+1.50)
-13.20 to +2.12 (TYP.-3.54)