Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 180)

Publication 900-UM007D-EN-E - January 2011
4-44 Parameter Adjustments & Application Considerations
Alarm Delays Alarm Delays
For 900-TC8 and 900-TC16, ON and OFF timed delays can be configured for
the Alarm Outputs 1, 2, and 3. For 900-TC32, ON and OFF timed delays can
be configured for the Alarm Output 1.The ON and OFF delay for Alarm 1
operate only for the alarm process function. If Alarm Output 1 is configured
as an OR with other alarm functions (i.e., the Heater Burnout Alarm, HS
Alarm, or input error output alarm), the time delay feature will not function
for the other alarms. The ON and OFF delays for alarms 1, 2, and 3 also apply
to the individual SUB1, SUB2, and SUB3 indicators and to communications
status. The alarm ON delays will also function when power is turned ON or
when moving from the Initial Setting function group to Operation function
group (i.e., to software resets). All outputs will turn OFF and the OFF delays
will not function when moving to the Initial Setting function group or when an
alarm is output for an A/D converter error.
Operation of Alarm ON and OFF Timed Delays (for an Upper-limit Alarm)
Figure 4.83
• The alarm will not turn ON if the time that the alarm is ON is equal to
or less than the configured ON delay configured time. Also, the alarm
will not turn OFF if the time that the alarm is OFF is equal to or less
than the OFF delay configured time.
• If an alarm turns OFF and then back ON during the ON delay time, the
time will be reset from the last time the alarm turns ON. Also, if an
alarm turns ON and then back OFF during the OFF delay time, the
time will be remeasured from the last time the alarm turns OFF.
PV
Alarm setting
Alarm hysteresis
Alarm status
ON delay
set time
ON delay set time
OFF delay
set time
Alarm Latch = OFF
Alarm will not turn ON.
Alarm ON Condition