Emerson Process Management ControlWave EFM 3808 - Manual (Page 41)

CI-ControlWave EFM Introduction / 1-25
The following items are stored in the Daily Data Log.
• Corrected Volume
• Uncorrected Volume
• Accumulated Energy
• Average Static Pressure
• Average
Temperature
• Average Differential Pressure
• Average Specific Gravity
• Average Heating Value
• Flow
Time
• Uncorrected Count
Each log entry also contains the date and time. The ControlWave EFM has a Daily
Historical Log for each of four runs.
1.5.3.3 Periodic Historical Data Log
The periodic data log holds one record for every log interval. Log interval is 15 minutes. The
Periodic Historical Data Log holds 1440 records, or four days of 15 minute data.
The following items are stored in the Periodic Historical Data Log:
• Flowing Differential Pressure
• Flowing Static Pressure
• Flowing
Temperature
• Frequency
Each log entry also contains the date and time. The ControlWave EFM has a Periodic
Historical Data Log for each of four runs.
1.5.3.4 Alarm and Event Storage
The ControlWave EFM keeps an Audit Trail Buffer capable of storing the most recent 500
Alarms and the most recent 500 Events. Internally, these buffers are maintained
separately to prevent recurring alarms from overwriting configuration audit data.
Externally, they are reported to the user as a single entity. Both operate in a circular
fashion with new entries overwriting the oldest entry when the buffer is full.
The following circumstances cause an entry to be made in the Audit Trail Buffer:
• Any operator change to a ControlWave EFM configuration variable
• Any change in the state of a ControlWave EFM alarm signal
• A system restart
• Certain other system events
1.5.4 LCD Display
In normal operation, the display stays off after the unit is configured and placed in service.
The operator may activate the display at any time by pressing the front panel button.
When activated, the display scrolls through a list of current values. The list defaults to an
appropriate set of values.