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Chapter 4. Functions
Note
•
If "heater burnout detection," "Overcurrent detection," and "Short-circuit
detection" are set to ON (detection status), ON (detection status) is retained even
if the delay timer reset conditions are satisfied.
To set to OFF (disabled), set to the "no current measurement" status.
•
If CT operation is set to "0: Continuous current measurement," the delay timer is
updated constantly every 1 ms.
•
If CT operation is set to "1: Detection of heater burnout for terminal OUT,"
the delay timer is updated every 1 ms based on the ON/OFF status of the OUT
terminal that is being monitored.
For "heater burnout detection" and "overcurrent detection," the current at output
ON is monitored, so the delay timer is updated only for the period when the
output of the OUT terminal being monitored is ON.
For "short-circuit detection," the current at output OFF is monitored, so the delay
timer is updated only for the period when the output of the OUT terminal being
monitored is OFF.
As an example, heater burnout detection uses the operation shown in the
diagram below.
Current when output ON
Delay timer is not updated when OUT
terminal being monitored is OFF
Heater burnout detection
current value
OUT terminal being monitored
Time
Time
Delay timer
Delay time
ON
OFF
Heater burnout detection
ON
OFF
Hysteresis
