Watlow CLS - Manual (Page 96)

88 CLS User’s Guide
Setup
Global Alarms
Global alarms occur when a loop alarm set to Alarm (not Control) is
unacknowledged, or when there are any unacknowledged failed sensor
alarms. (If an alarm occurs, the CLS front panel displays an appropriate
alarm code--see Using the CLS section.) Even if the alarm condition
goes away, the global alarm stays on until you use the front panel
Alarm Ack key (or ANASOFT) to acknowledge it.
Process Alarms
Process alarms include high and low deviation and high and low process
alarms. You can set each of these alarms to Off, Alarm, or Control, as
shown here.
• High process and high deviation alarms activate when the process
variable goes above a value you set. They remain active until the
process variable goes below that value minus the deadband. (See the
next diagram)
• Any digital output not used as a control output can be assigned to one
or more process variable alarms. The output is active if any of its
alarms are active. All alarm outputs are active Low or active High,
depending on the global alarm output polarity setting.
• Low process and low deviation alarms activate when the process
variable goes below a value you set. They remain active until the
process variable goes above that value plus the deadband. (The next
diagram shows these alarms.)
Function Description
Off No alarm or control function
Alarm Standard alarm function
Control Digital output activities on alarm, deactivates
when loop is not in alarm. Global alarm output
does not activate.