Logix5000 Controllers General Instructions - SLAC Confluence

54 Analog Alarm Instruction (ALMA)Input Parameter Data Type DescriptionMinDurationPRE DINT Specifies the minimum duration preset for the alarm In value to be in any level-basednon-normal condition before the alarm notification is sent to clients (milliseconds). Does notapply to Rate of Change limits. Once the minimum duration preset it reached, any alarmnotifications for subsequent alarm level events are sent immediately. The minimum durationtime will be reset once the alarm returns to normal.Valid = 0 to 2147483647.Default = 0.Deadband REAL Specifies the deadband for detecting that high-high, high, low, and low-low alarm levels havereturned to normal.Valid = 0.0 to maximum possible float.Default = 0.0.ROCPosLimit REAL Specifies the limit for an increasing rate-of-change in units per second. Detection is enabled forany value > 0.0 if ROCPeriod is also > 0.0.Valid = 0.0 to maximum possible float.Default = 0.0.ROCPosSeverity DINT Specifies the severity of the increasing rate-of-change alarm condition.Valid = 1 to 1000 (1000 = most severe; 1 = least severe).Default = 500.ROCNegLimit REAL Specifies the limit for a decreasing rate-of-change in units per second. Detection is enabled forany value > 0.0 if ROCPeriod is also > 0.0.Valid = 0.0 to maximum possible float.Default = 0.0.ROCNegSeverity DINT Specifies the severity of the negative rate-of-change alarm condition.Valid = 1 to 1000 (1000 = most severe; 1 = least severe).Default = 500.ROCPeriod REAL Specifies the time period in seconds for calculation of the ROC value. This value specifies thesampling interval for calculating the ROC value. Each time the sampling interval expires, thedifference between the current sample and the previous sample is divided by the time interval.Rate-of-change detection is enabled for any value > 0.0.Valid = 0.0 to maximum possible float.Default = 0.0.Publication 1756-RM003I-EN-P - January 2007