Mitsubishi MELSEC Q series User Manual page 77

(11)When "Sampling" is set to "Step No. specification"
With "Sampling" set to "Step No. specification", the processing time of data logging is added to the program
running time. Accordingly, when "Step No. specification" is specified, design watchdog timer settings and
interrupt programs with a consideration of the processing time of data logging (setting the fixed scan interval).
(12)Sampled data being saved to an SD memory card
If the CPU module is powered off or reset while data in the buffer is being saved to an SD memory card, unsaved
data will be cleared. However, data will be saved without being cleared in the following cases.
• Status change from RUN to STOP
• Pause caused by turning off the special relay (Data logging start)
• Stop or pause operation from the configuration tool
• Execution of the trigger logging reset instruction (LOGTRGR)
(13)Changing clock data
Do not change clock data of the CPU module during execution of data logging. Doing so will cause incorrect
"Date" column information to be output to the CSV file. (Even if clock data are changed, data are collected at the
specified intervals or timing. Therefore, changed clock data will be output in the Date column of the CSV file.)
(14)Sampling timing when the display unit is attached
An error of up to 100s may occur in the sampling timing when the display unit is attached.
Ex. A time value is set for "Time specification" of "Sampling", without setting of data sampling at the END
processing.
(15)Removing the SD memory card
When data logging is being executed with the data logging setting stored in an SD memory card, the
corresponding bit of SD604 (Memory card use conditions) turns on.
Because of this, the following LEDs do not turn off when the removal operation is performed.
• SD CARD LED of the High-speed Universal model QCPU and Universal model Process CPU: when the SD
memory card access control switch is pressed for 1 second or longer
• SD LED of the LCPU: when the SD memory card access control switch is slid up
To remove the SD memory card in the above case, stop the data logging processing and remove the SD memory
card again. For details on the removal procedure, refer to the following. For details on the removal procedure,
refer to the following.
User's Manual (Hardware Design, Maintenance and Inspection) for the CPU module used
(16)Using data that are set by a CPU module of a different series
If the High-speed Universal model QCPU or Universal model Process CPU executes data logging using the
settings stored in an SD memory card by a CPU module of a different series, an error occurs. ( Page 180,
Section 13.1)
Since the LCPU can use the settings stored in an SD memory card by a CPU module of a different series, no
error occurs.
CHAPTER 6 DATA LOGGING FUNCTION
6
75