Emerson PN 51-FCL-1056 instruction manual Section Programming the Analyzer

MODEL FCL-1056

5.4.2 Definitions

1.ASSIGNING ALARMS. There are four alarms relays. The relays are freely assignable to any sen- sor and to either the measurement (for example, chlorine) or temperature. Alarm relays can also be assigned to operate as interval timers or as fault alarms. A fault alarm activates when the analyzer detects a fault in either itself or the sensor.

2.FAULT ALARM. A fault condition exits when the analyzer detects a problem with a sensor or with the analyzer itself that is likely to cause seriously erroneous readings. If an alarm was programmed as a fault alarm, the alarm will activate. At the same time a fault message will appear in the main dis- play.

3.ALARM LOGIC, SETPOINTS, AND DEADBANDS. See Figures 5-1 and 5-2.

4.INTERVAL TIMER. Any alarm relay can be used as an interval timer. Figure 5-3 shows how the timer operates. While the interval timer is operating, the main display, analog output, and assigned alarms for the sensor(s) can be put on hold. During hold, the main display remains at the last value.

5.SYNCHRONIZE TIMER. If two or more relays are being used as interval timers, choosing synchro- nize timers will cause each timer to start one minute later than the preceding timer.

SECTION 5.0

PROGRAMMING THE ANALYZER

FIGURE 5-1. High alarm logic. The alarm activates when the chlorine concentration exceeds the high set- point. The alarm remains activated until the reading drops below the value determined by the deadband.

FIGURE 5-2. Low alarm logic. The alarm activates when the chlorine concentration drops below the low set- point. The alarm remains activated until the reading increases above the value determined by the dead-band.

FIGURE 5-3. Operation of the interval timer. The num- bers in parentheses are the allowed values for each timer parameter.

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