Installation manual

Series C Controller Configuration and Operation Manual
9-4  Athena Controls, Inc. 900M050U00
9.2.2 Choosing the Alarm Operation
Unless the output will be used to signal ramp/soak recipe event, the second step in
configuring an alarm is to choose the alarm operation. The choices are:
• process alarm – Activated when the process variable reaches the alarm value
(alarm setpoint parameter value), independent of the PV’s relationship to the
process setpoint. A high process alarm activates at and above the alarm
setpoint. A low process alarm activates at and below the alarm setpoint. For
example, if you want an alarm to alert the operator when the PV goes up to 200,
then configure the alarm as a high process alarm, and specify the alarm setpoint
as 200.
• deviation alarm – Activated when the process variable deviates from the
process setpoint by the amount specified using the alarm value (alarm setpoint
parameter value). A high deviation alarm activates when the PV is above the
process setpoint by the amount specified using the alarm value. A low deviation
alarm activates when the PV is below the process setpoint by the amount
specified using the alarm value. For example, if you want an alarm to alert the
operator when the PV is 50 below the setpoint, then configure the alarm as a low
deviation alarm, and specify the alarm value (using the alarm setpoint parameter)
as 50.
• inverse band alarm – Activated when the process value is within a specified
band centered around the setpoint. For example, if you want the alarm to alert
the operator when the PV is 10 units (or less) above or below the process
setpoint, then configure the alarm as an inverse band alarm, and specify 10 for
the alarm setpoint parameter value.
• normal band alarm – Activated when the process value is outside a specified
band centered around the setpoint. For example, if you want the alarm to alert
the operator when the PV is 10 units (or more) above or below the process
setpoint, then configure the alarm as a normal band alarm, and specify 10 for the
alarm setpoint parameter value.
Parameter Name:
Alarm 1 Operation (C3) and Alarm 2 Operation (C9)
Name as Displayed
:
A1.AOA1.AO and A2.A0A2.A0
Used By:
all except 1ZC
When Displayed:
if alarm action is not event
Choices:
Pro.LPro.L low process alarm
Pro.HPro.H high process alarm
in.bin.b inverse band
nor.bnor.b normal band
de.Lde.L low deviation alarm
de.Hde.H high deviation alarm
Default:
alarm 1: process high
alarm 2: process low
Description:
Used to choose the alarm operation.
Effect on Other
Parameters:
Determines how the value of the A1.SPA1.SP or A2.SPA2.SP (alarm setpoint)
parameter is used.