Watlow CPC400 - Manual (Page 156)

Chapter 6: Troubleshooting and Reconfiguring CPC400 Series User’s Guide
142 Watlow Anafaze Doc. 0600-2900-2000
Responding to a Process Alarm
Your response to an alarm depends upon the alarm func-
tion setting, as explained in Table 6.1.
Table 6.1 Operator Response to Process
Alarms
Failed Sensor Alarms
When a failed sensor alarm occurs, the controller switches
to the single loop display for the loop with the alarm and
displays an alarm code (see Alarm Displays on page 51).
WatView software displays a message on the alarm screen
and logs the alarm in the event log.
A failed sensor alarm clears once it has been acknowledged
and the sensor is repaired. For more information about the
causes of failed sensor alarms, see Failed Sensor Alarms on
page 63.
Disable Failed Sensor Functions
When a loop uses the Soft Integer for a PV Source, some
failed sensor functions are disabled. These include func-
tions that require linkages between specific thermocouple
or RTD input and loop outputs to operate correctly. When
a loop uses a soft integer as the PV Source, the thermocou-
ple or RTD no longer has a direct relationship to a specific
loop output.The failed sensor functions disabled are:
• Thermocouple Short Alarm (Global)
• Reversed Thermocouple Detection (Loop)
• Restore Automatic Mode (Loop)
• Sensor Fail Heat/Cool Output (Loop)
This parameter will switch a loop to manual mode at
the specified output power if a failed sensor alarm oc-
curs or the mode override input becomes active. Only
the function that sets the output based on a failed sen-
sor is disabled.
• Open Thermocouple Heat/Cool Output Average (Loop)
Alarm
Function
Operator Response
Boost
The operator does not need to acknowledge
the alarm. The alarm clears automatically
when the process variable returns within lim-
its.
Standard
Acknowledge the alarm by pressing x on
the keypad or by using HMI software. The
alarm clears after the operator acknowl-
edges it
and the process variable returns
within the limits.