Extech Instruments 96VFL Series - Alarm Function and Alarm Modes Lists

VFL Series User Manual v2.0 10/20
28
11.3 Alarm Function and Alarm Modes Lists
ALARM FUNCTION LIST
Once a function is programmed in the ‘A1Fu’ and ‘A2Fu’ parameters (Menu 4, Options), set
the setpoint in Menu 1 (‘A1SP’ or ‘A2SP’). For Alarm ON/OFF Timers, set the timer in Menu
4, Options (‘P.TME’). See the separate section on Alarm ON/OFF Timers for details.
‘A1FU’ / ‘A2FU’
setting
Alarm Type
Operation
No Alarms
No Alarms
Process
High alarm
Relay trips when the process (PV) exceeds the ‘AxSP’
value (Menu 1).
Process
Low alarm
Relay trips when the process (PV) falls below the ‘AxSP’
value (Menu 1).
Deviation
High alarm
The Alarm setpoint equals the Setpoint (SV) plus the
‘AxSP’ (Menu 1) setting. For example, if SV = 400 and
A1SP = +10 then the Alarm relay will trip when the
temperature rises above 410
o
(400 + 10 = 410).
Deviation
Low alarm
The Alarm setpoint equals the Setpoint (SV) plus the
‘AxSP’ setting. For example, if SV = 400 and A1SP = -10
then the Alarm relay will trip when the temperature falls
below 390
o
(400 – 10 = 390).
Band High
alarm
Alarm trips when PV is higher than the setpoint band.
Band Low
alarm
Alarm trips when PV is lower than the setpoint band.
ON-Timer
See dedicated ON/OFF Alarm Timer section.
OFF-Timer
See dedicated ON/OFF Alarm Timer section.