Mitsubishi Electric MELSEC iQ-R User Manual page 78

Logging status monitor value
The execution status of logging can be checked with 'CH1 Logging status monitor value' (Un\G458).
Stored value of 'CH1 Logging status monitor value' (Un\G458)
FH
0H
1H
2H
3H
Checking logging data without stopping the logging operation
Logging data can be checked during the logging operation with 'CH1 Head pointer' (Un\G436, Un\G437), 'CH1 Latest pointer'
(Un\G438, Un\G439), and 'CH1 Number of logging data' (Un\G440, Un\G441).
To check logging data during the logging operation, follow the precautions below because logging data may be updated while
data is being read.
• Set the cycle to 'CH1 Logging cycle setting value' (Un\G538) so that checking and reading of data surely is completed
before logging data is updated. If the logging cycle is short, logging data may be updated during checking and reading of
data.
• After obtaining the logging data which needs to be checked, monitor the change of 'CH1 Head pointer' (Un\G436, Un\G437)
or 'CH1 Number of logging data' (Un\G440, Un\G441), and obtain logging data just after the stored value has changed.
• If the updated data and the data being checked do not synchronize due to the relationship between the logging cycle and
the scan time of the CPU module, adjust the logging cycle.
Stop the logging operation when the logging data needs to be checked without paying attention to the logging cycle. (
Page 77 Stopping the logging operation)
1 FUNCTIONS
76
1.14 Normal Logging Function
Execution status of logging
Stop (disabled)
Logging hold request waiting (during logging)
Level trigger waiting (during logging)
Trigger existing (during logging)
Logging hold completed (stop)