Overview of Alarms
Chapter Three: Overview
86
Overview of Alarms
From a design viewpoint, the alarm system in the 146 unit consists of several, single pole, double
throw relays. Two alarms (A and B) come standard with the 146 unit and are available on the
General I/O connector. The optional Auxiliary Output board provides two additional alarms (C
and D).
From an operational viewpoint, the alarm system consists of user-defined alarm trip points,
user-defined relay untripped states, a user-defined relay latching state, and front panel window
displays. Also, users can turn individual alarms, or the entire alarm audio system, on or off.
Individual alarms can be turned on/off in Normal or Leakage Modes (refer to How To Turn an
Alarm On or Off, in either the Operation in Normal Mode or Operation in Leakage Mode
chapter). When an individual alarm is turned off, the alarm’s relay will be in its deactuated state,
and nothing associated with that alarm (alarm audio tone, alarm diamond display, or alarm relay
activity) will change regardless of the pressure.
Alarm trip points are entered, and individual alarms can be turned on/off (enabled/disabled) in
Setup Mode (refer to How To Set Alarm Trip Points, in the Operation in Setup Mode chapter).
The alarm audio tone (a continuous high tone) can be permanently turned on/off in Setup Mode
(refer to How to Adjust Alarms, in the Operation in Setup Mode chapter).
To understand how to configure the alarm relay system in the 146 unit, it is necessary to
understand what an alarm condition means. In the 146 instrument, an alarm condition exists
when pressure rises above the alarm trip point pressure. The alarm condition is indicated by
a diamond on the left side of the front panel, and an alarm audio tone. In addition, if the alarm is
set to remain latched after an alarm condition ceases (the pressure drops below the alarm trip
point), then a
LATCHED
legend also appears on the front panel.
The first alarm relay parameter to set up is the relay untripped state. Actuation and deactuation
simply refer to how an alarm relay is configured during a non-alarm condition. The relay
untripped state is adjusted in Setup Mode. Individual alarms can be assigned an actuated or
deactuated state.
When a relay is set up as actuated, the letter A appears in the center display when adjusting the
alarm trip point in Setup Mode. When a relay is set up as deactuated, the letter d appears in the
center display. Refer to How To Set Alarm Trip Points in the Operation in Setup Mode chapter,
for instructions on how to change the actuation state of an alarm. If a relay is set up as a
deactuated relay and an alarm condition arises, the relay will respond as shown in Figure 22.
(The signals are available on the General I/O connector.)
Normally Open (Pin 11)
Normally Closed (Pin 13)
Relay B Common
(Pin 12)
Figure 22: Relay B during an Alarm Condition, when configured as a Deactuated Relay
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
