V1.00, August 30, 2004644.10 Setting Output Control With AlarmThe TTC-1000 monitors two critical conditions: processor (DEVICE) andtemperature (TPROBE) and allows the user to control how each output reactswhen an alarm occurs. A DEVICE alarm occurs anytime the microprocessordetects a failure in any of the peripheral hardware including the non-volatile E 2memory, the real time clock, analog outputs, corruption of stored data and powersupply brown out.The TPROBE alarm is generated anytime the processor is unable to obtainreliable temperature information. This failure can be due to a discontinuity in theleads connected to the temperature probe or with any of the internal circuitryassociated with the analog to digital conversion process. All temperature setpoint evaluations are suspended until the alarm condition is cleared.The TTC-1000 allows you to program how an output will react whenever there isa DEVICE or TPROBE alarm. There are three (3) ways an output can reactwhenever there is a DEVICE or TPROBE alarm:1. Unchanged (UNCHG): the output remains as it was prior to thealarm.2. Picked Up (PCKUP): the output picks up when alarm occurs.3. Supervised (SUPVS): the output drops out when alarm occurs.The TTC-1000 output control default is UNCHG for each output.The user should decide how they wish each output to operate whenever there iseither a DEVICE or TPROBE alarm. For example if OUT1 and OUT2 control twoseparate banks of fans, it might be desirable to have OUT1 and OUT2 pickup assoon as a DEVICE or TPROBE alarm occur. This insures that the fans arerunning even though there might be a device or temperature probe failure.NOTE: It is strongly recommended to set output control to supervised(SUPVS) for all outputs controlling cooling fans in fail-safe mode.However, if OUT3 is used for a trip signal, it may be desirable to use the DEVICEor TPROBE alarm to supervise OUT3. This will insure that a trip signal is blockedwhenever a DEVICE or TPROBE alarms occur.Also, if OUT4 is used for a high temperature alarm, it may be desirable for OUT4to remain unchanged if a DEVICE or TPROBE alarm occurs. This will insure thata high temperature alarm continues to be reported.Programming from the front panel, press the %%%%or &&&&arrow button until the setting113 is displayed:PRGM SETTING 113OUT1UNCHGw/ALRM
