Configuring Alarms And Assigning Setpoints; High Alarm Logic; Low Alarm Logic - Emerson Rosemount Analytical FCLi Instruction Manual

MODEL FCLi

5.4 CONFIGURING ALARMS AND ASSIGNING SETPOINTS

5.4.1 Purpose
This section describes how to do the following:
1. assign an alarm relay to a sensor,
2. set the alarm logic to high or low,
3. assign values to the alarm setpoints,
4. set the alarm deadbands.
ALARM RELAYS MUST BE CONFIGURED BEFORE ASSIGNING SETPOINTS.
5.4.2 Definitions
1. ASSIGNING ALARMS. There are three alarms (AL1, AL2, and AL3). The alarms can be assigned to either
sensor. For example, AL1 and AL2 can be assigned to sensor 1 with, perhaps, one alarm configured as a high
alarm and the other as a low alarm, and AL3 can be assigned to sensor 2. Alarm 3 can also be used as a fault
alarm. The fault alarm activates when a fault exists in a sensor or the analyzer.
2. FAULT ALARM. A fault condition exists when the Model FCLi analyzer detects a problem with a sensor or with
the analyzer that is likely to cause seriously erroneous readings. If Alarm 3 was programmed as a fault alarm,
the alarm 3 relay will activate. The word Fault will appear alternately in the display with the reading.
3. ALARM LOGIC, SETPOINTS, AND DEADBANDS. See Figures 5-2 and 5-3.
FIGURE 5-2. High Alarm Logic
The alarm activates when the pH exceeds the high
setpoint. The alarm remains activated until the reading
drops below the value determined by the deadband.
Alarm relays are single pole-double throw (SPDT). When an alarm is activated, the coil is energized.
When an alarm activates, AL1, AL2, or AL3 (as appropriate) appears periodically in the display.
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FIGURE 5-3. Low Alarm Logic
The alarm activates when the chlorine concentration
drops below the low setpoint. The alarm remains acti-
vated until the reading increases above the value deter-
mined by the deadband.
SECTION 5.0
PROGRAMMING THE ANALYZER