Watlow CLS200 - Manual (Page 83)

CLS200 Series User’s Guide Chapter 3: Using the CLS200
Doc.# 0600-3050-2000 Watlow Anafaze 67
What Happens If a Process Alarm Occurs?
If a process alarm occurs, the controller does the following:
• Shows an alarm code on the display. (See Alarm Dis-
plays on page 58.) .
• Activates the global alarm output. (See Global Alarm
on page 68.)
• Activates the digital output that is assigned to the pro-
cess alarm (if applicable). The digital output remains
active until the process variable returns within the
corresponding limit and deadband. The alarm output
deactivates when the process returns to normal.
Process Alarm Outputs
Any digital output that is not used as a control output can
be assigned to one or more process alarms.
The controller activates the output if any alarm assigned to
the output is active. Process alarm outputs are non-latch-
ing—that is, the output is deactivated when the process re-
turns to normal, whether or not the alarm has been
acknowledged.
Specify the active state of process alarm outputs at the DIG
OUT POLARITY ON ALARM setting in the SETUP GLOBAL
PARAMETERS.
Alarm Type: Control or Alarm
You can configure each process alarm as either a control or
alarm.
• Alarm configuration provides traditional alarm func-
tionality: The operator must acknowledge the alarm
message on the controller display, a latching global
alarm is activated, and the alarm can activate a user-
specified non-latching alarm output.
• Control configuration provides on/off control output
using the alarm setpoints. For example, you could con-
figure a high deviation alarm to turn on a fan. The
alarm activates a user-specified non-latching output.
Alarm messages do not have to be acknowledged, and
the global alarm is not activated.
High and Low Process Alarms
A high process alarm occurs if the process variable rises
above a user-specified value. A low process alarm occurs if
the process variable drops below a separate user-specified
value. See Figure 3.9.
Enter the alarm high and low process setpoints at the HI
PROC ALARM SETPT and LO PROC ALARM SETPT param-
eters in the SETUP LOOP ALARMS menu.