# Channel State Changes

This type of session deals with any change in the state (Alarm, Normal, etc.) of any channel. Data would typically be directed to a Log File or to a local data logger (LDL or serial printer).

Note: The state of a channel is distinct from its current reading or value.

Example:

Channel 1 is monitoring the water level of a tank. Channel 1 has been configured for low and high set points. The high setpoint is configured to trip at 35 feet. When the water level is within the configured set points the Channel 1 message would read:

Water level reading is 30 feet NORMAL

The tag word NORMAL indicates the channel is operating within desired limits. When the water level exceeds 35 feet the Channel 1 message would read:

Water level reading is 37 feet ALERT

The tag word ALERT indicates the channel is not operating within desired limits. If this violation condition persists for the duration of the Alarm Trip Delay, the Channel 1 message would read:

Water level reading is 37 feet HIGH SETPOINT ALARM

The tag words HIGH SETPOINT ALARM indicate the channel is not operating within desired limits for longer than the alarm trip delay. At this point, the Catalyst would be attempting to notify those destinations configured for notification reports. When the alarm is acknowledged, the Channel 1 message would read:

Water level reading is 37 feet HIGH SETPOINT ALARM ACKNOWLEDGED

The tag word ACKNOWLEDGED is added to HIGH SETPOINT ALARM to indicate the alarm has been acknowledged by a notification destination. When the water level is back within operating parameters, the Channel 1 message would read:

Water level reading is 33 feet HIGH SETPOINT ALARM ACKNOWLEDGED NOW NORMAL

The tag words NOW NORMAL indicate the channel is now back within operating tolerances. At this point, the Catalyst will wait until the Alarm Reset Timer is completed. If the channel remains within tolerances, the Channel 1 state would once again be:

Water level reading is 33 feet NORMAL