RSView Supervisory Edition Installation Guide

• • • • •RSVIEW SUPERVISORY EDITION USER’S GUIDEThe following illustration shows an increasing threshold of 4,000 rpm with a deadbandvalue of 500 rpm. The rpm has to fall to 3,500 and then rise above 4,000 before it willtrigger the alarm again.rpm5,000In alarmIn alarmagainThreshold4,0003,5003,0002,000Out of alarmDeadband1,0000TimenA deadband range may be absolute, as illustrated above, or it may be a percentage of theminimum/maximum range for a tag. If the deadband in the illustration were two percent,its range would be two percent of 5,000 rpm, or 100 rpm.If a buffer is not required, the deadband must be set up as zero. With a deadband of zero,alarms will be triggered as soon as the tag value crosses any of its thresholds.Use the deadband carefully in safety-critical applications. In the above illustration, the variablehas to fluctuate by more than 500 rpm before an alarm is triggered again.Alarms for digital HMI tagsDigital tags are either on or off. Instead of thresholds, digital tags have alarm states.This alarm stateOnOffDoes thisTriggers an alarm when a tag has a valueof 1.Triggers an alarm when a tag has a valueof 0.11-6