Display of previous and current analog states in alarm and event messages

Administrators can configure the system to display the previous and current states of analog points in alarm and event messages. The change applies to most, but not all, types of alarms.

For the following types of alarms, the alarm and event messages generated by the system can display both the previous and current states of the point when so configured:

• HiLo alarms

  Examples:

  • LOW-LOW from NORMAL - Value = 8 PERCENT (LOW-LOW state), [Limit = 10]

  • NORMAL from LOW-LOW - Value = 60 PERCENT (NORMAL state)

• Instrument Fail alarms

• Special non-persistent alarms (Rate-Of-Change (ROC) alarms of type "Custom Method")

  Examples:

  • ROC from NORMAL - Value= 99PERCENT(ROC state), last=10, ROC=17.8000, pos limit 5.0000 neg limit - 8.000

  • NORMAL from ROC - Value= 99PERCENT(NORMAL state), last=99, ROC=0.0000, pos limit 5.0000 neg limit - 8.000

• Setpoint Creep alarms (an analog point moving from any state into a Setpoint Creep state or vice versa)

  Examples:

  • SETPOINT CREEP from NORMAL - Value = 91 PERCENT (SETPOINT state), [Limit = 40][50.0000]

  • NORMAL from SETPOINT CREEP - Value = 89 PERCENT (NORMAL state)

For the following types of alarms, the alarm and event messages generated by the system do not display the previous state of the point:

• User-defined HiLo alarms.

• Non-persistent alarms (Rate-Of-Change (ROC) alarms of type "Baseline Method" and Creep (deviation) alarms)

  Examples:

  • ROC - Value= 99PERCENT(ROC state), last=10, ROC=17.8000, pos limit 5.0000 neg limit - 8.000

  • ROC - Value= 99PERCENT(NORMAL state), last=99, ROC=0.0000, pos limit 5.0000 neg limit - 8.000