Flowserve MX FOUNDATION Fieldbus Field Unit - Manual (Page 70)

MX/QX FOUNdaTION Fieldbus Field Unit FCd LMENIM2330-01 – 08/11
70
C
Appendix –
Fieldbus Parameter
Descriptions
FOUNDATION Fieldbus employs the following standard parameter definitions associated with the
control Function Blocks.
ACK_OPTION
Selection of whether alarms associated with the block will be automatically acknowledged.
ALARM_HYS
Amount the PV must return within the alarm limits before the alarm condition clears. Alarm
Hysteresis is expressed as a percent of the PV span.
ALARM_SUM
The current alert status, unacknowledged states, unreported states, and disabled states of the alarms
associated with the function block.
ALERT_KEY
The identification number of the plant unit. This information may be used in the host for sorting
alarms, etc.
BAL_TIME
This specifies the time for the internal working value of bias or ratio to return to the operator set bias
or ratio, in seconds.
In the PID block, it may be used to specify the time constant at which the integral term will move to
obtain balance when the output is limited and the mode is Auto, Cas, or RCas.
BIAS
The bias value used in computing the function block output, expressed in engineering units.
BKCAL_HYS
The amount that the output must change away from its output limit before the limit status is turned
off, expressed as a percent of the span of the output.
BKCAL_IN
The value and status from a lower block’s BKCAL_OUT that is used to prevent reset windup and to
initialize the control loop.