Section 6: Meter operation

Reference, Installation, and Operations Manual

June 2013

3-9000-743 Rev S

 

 

6.6.4Alarm log

The Mark III meter monitors several data points with respect to each point’s alarm limit(s). Non- boolean data points can have low and high alarm limits. Boolean data points only have a single alarm limit (i.e., either TRUE or FALSE). There are two statuses associated with alarms: set and cleared. An alarm is set when the data point is at or exceeds its alarm limit. An alarm is cleared when the data point is within its alarm limit(s).

The Mark III meter stores an alarm log record whenever any monitored data point’s alarm status (cleared or set) changes. The alarm log record indicates the data point, date and time, alarm status, corresponding alarm limit, and data point value.

The meter can store up to 3000 alarm records. The user can select whether old, unread records can be overwritten by new records when the log becomes full via the data point DoOverwriteUnreadAlarmLog. This point can be modified using the Daniel MeterLink Tools - Edit/Compare Configuration screen. The default is to overwrite old, unread records. Refer to Section 6.6.6 for information on reading records and marking records as read. The data point IsAlarmLogFull indicates whether or not the alarm log is full and cannot overwrite old, unread records.

The user-settable data points AlarmTurnOffHysterisisCount and AlarmTurnOffHysterisis- TimeSpan are used to prevent very repetitive alarms from filling up the alarm log. When an alarm is set AlarmTurnOffHysterisisCount times within AlarmTurnOffHysteresisTimeSpan seconds, then the alarm is suppressed until the alarm frequency drops below the specified rate (counts per time span) at which point the next alarm clearing “unsuppresses” the alarm. The alarm log records indicate when an alarm suppression is started and ended. The default values are 8 occurrences in 240 seconds.

The data points monitored for the alarm log are as shown in Table 6-21and Table 6-22below. Note that the alarm limits are themselves data points. The user-settable alarm limits are listed by data point name. Non-settable alarm limits are listed by data point value.

Table 6-21 Alarm log non-boolean data points monitored

Data Point

Low Alarm LimitHigh Alarm Limit

 

 

 

GainAUp, GainADn,

GainLowLmt

GainHighLmt

GainBUp, GainBDn,

 

 

GainCUp, GainCDn,

 

 

GainDUp, GainDDn

 

 

 

 

 

AvgSndVel

AvgSoundVelLoLmt

AvgSoundVelHiLmt

 

 

 

AGA8BaseCalcStatus

 

1

 

 

 

AGA8FlowCalcStatus

 

1

 

 

 

SpecFlowPressure

LowPressureAlarm

HighPressureAlarm

 

 

 

SpecFlowTemperature

LowTemperatureAlarm

HighTemperatureAlarm

 

 

 

LiveFlowPressure

LowPressureAlarm

HighPressureAlarm

 

 

 

LiveFlowTemperature

LowTemperatureAlarm

HighTemperatureAlarm

 

 

 

250

Alarm log