Watlow PPC-2000 - Manual (Page 221)

PPC-2000 User’s Guide Chapter 5: LogicPro and Modbus Reference
Doc.# 30002-00 Rev 2.3 Watlow Anafaze 193
High Process Limit (HP Limit)
The high process alarm activates when the Process Variable (PV)
goes above the high process setpoint. The PV must drop to the
alarm setpoint minus the alarm deadband for the alarm to
clear. The alarm limit is set in the engineering units of the
channel. Its value does not change when the process setpoint
changes. The default high process alarm setpoint is 0.
Low Process Limit (LP Limit)
The low process alarm activates when the process variable (PV)
goes below the low process setpoint. The PV must rise to the
alarm setpoint plus the alarm deadband for the alarm to clear.
The alarm limit is set in the engineering units of the channel.
Its value does not change when the process setpoint changes.
The default low process alarm setpoint is 0.
High Deviation Offset (HD Offset)
This value determines the high deviation alarm limit relative
to the current setpoint. The high deviation alarm occurs when
the process variable is greater than the current setpoint plus
this value. The offset is set in the engineering units of the
channel but relative to the process setpoint. The alarm limit
changes when the process setpoint changes. The default high
deviation offset is 0.
Low Deviation Offset (LD Offset)
This value determines the low deviation alarm limit relative to
the current setpoint. The low deviation alarm occurs when the
process variable is lower than the current setpoint less this
value. The offset is set in the engineering units of the channel
but relative to the process setpoint. The alarm limit changes
when the process setpoint changes. The default low deviation
offset is 0.
Alarm Deadband
This parameter prevents the process and deviation alarms
from toggling on and off when the process variable is near the
alarm limit. For high alarms the deadband is below the
setpoint; for low alarms the deadband is above the setpoint. An
alarm that occurs when the process variable crosses the alarm
setpoint does not clear until the process returns within the
alarm setpoint and the deadband value. The deadband is set in
the engineering units of the channel. The default alarm
deadband is 2.