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Chapter 4. Functions
z
Condition for restoring status before measurement
Set the standard bit code as the determining condition for restoring the CT value to
the "no current measurement" status.
This function is used to cancel burnout detection that continues while control has
stopped after burnout is detected.
Note
•
The condition for restoring the status before measurement is used to disable
detection determination until a new CT current is measured so that the heater
burnout detection, overcurrent detection, and short-circuit detection are OFF
(disabled).
•
If the standard bit code specified for “Condition for restoring status before
measurement” is set to ON, there is no CT current measurement.
•
The ON status (detected status) of heater burnout detection, overcurrent
detection, and short-circuit detection is retained until it changes to the "no
current measurement" status. The "detected" status does not turn OFF (is not
canceled) even after the equipment error status is cleared.
To set "heater burnout detection," "overcurrent detection," and "short-circuit
detection" status to OFF (canceled), set the standard bit that is assigned to
"Condition for restoring status before measurement" to ON if no heater burnout,
overcurrent, or short-circuit is detected.
z
Timing for updating CT current measurement
If "CT operation" is set to "1: Detection of heater burnout for terminal OUT," the
current when the output turns ON and OFF is updated as shown below.
100 ms
100 ms
CT
measurement
wait time
CT
measurement
wait time
CT
measurement
wait time
CT
measurement
wait time
100 ms
100 ms
100 ms
100 ms
ON
OFF
Specified OUT
terminal output status
Previous current value retained
when output OFF
Current measurement
value updated
when output OFF
Current measurement
value updated
when output OFF
Previous current value
retained when output ON
Current measurement
value updated when
output ON
Current measurement
value updated when
output ON
When the ON or OFF status of the OUT terminal output has continued for the
wait time for CT measurement plus 100 ms or longer, the measured current when
the output turns ON/OFF is updated. If the ON or OFF output status of the OUT
terminal continues for less than the wait time for CT measurement plus 100 ms, the
previously measured current is kept without updating the current when the output
turns ON/OFF.
If the output becomes 0 % in READY mode or due to a temperature drop under
reverse action, the previous value is kept without updating the current value at
output ON.