Bfm #77: Number Of Times Of Alarm 1/2/3/4 Delay; Bfm #78: Number Of Times Of Heater Disconnection Alarm Delay - Mitsubishi Electric MELSEC FX2N-2LC User Manual

FX2N-2LC Temperature Control Block
7.2.36

BFM #77: Number of times of alarm 1/2/3/4 delay

In BFM #77, set the number of alarm delays. This setting is applied to all alarms 1 to 4.
The alarm delay function keeps the non-alarm status until the number of input samples
exceeds the number of alarm delays, after the deviation between the measured value (PV) and
the set value (SV) reaches the alarm set value.
If the deviation remains in the alarm range until the number of input samples exceeds the num-
ber of alarm delays, an alarm is issued.
The allowable set range is from 0 to 255 times. (input sampling cycle: 500 ms)
Example: When the number of alarm delays, is set to 5 times
Measured value (PV)
Alarm set value
Temperature
set value (SV)
Input sampling
Alarm status
7.2.37

BFM #78: Number of times of heater disconnection alarm delay

In BFM #78, set the number of heater disconnection alarm delays. This setting is applied to
both CH1 and CH2.
If the abnormal status consecutively occurs in the heater current measured value (sampling
cycle: 1 sec) by the preset number of times, an alarm is issued.
The allowable set range is from 3 to 255 times.
Measured value
(PV)
3 times 5 times
Buffer Memory (BFM) 7
Time
Non-alarm status
Alarm status
7-26