Reference Manual
00809-0100-4697, Rev EA
October 2011
D-7
Rosemount 848T
Status Handling
Normally, the status of the PV reflects the status of the measurement valu e,
the operating condition of the I/O card, and any active alarm condition. In Auto
mode, OUT reflects the value and st atus quality of the PV. In Man mode, the
OUT sta tus constant lim it is set to indicate that the value is a con stant an d the
OUT status is Good.
If the sensor limit exceeds the high or low range, PV status is set high or low
and EU range status is set to uncertain.
In the STATUS_OPTS paramete r, select from the following options to control
the status handling:
BAD if Limited
Sets the OUT status quality to Bad when the value is higher or lower than
the sensor limits.
Uncertain if Limited
Sets the OUT st atus qu ality to Uncertain when the value is higher or lower
than the sensor limits.
Uncertain if in Manual mode
The status of the Output is set to Uncertain when the mode is set to
Manual
NOTES
1. The instrument must be in OOS mode to set the status option.
2. The AI block only supports the BAD if Limited option, uncertain if limited,
and uncertain if manual.
Advanced Features
The AI function block provided with Rosemou nt fieldbus devices provides
added capability through the addition of the following parameters:
ALARM_TYPE
Allows one or more of the process alarm conditions detected by the AI
function block to be used in setting its OUT_D parameter.
OUT_D
Discrete output of the AI function block based on the detection of process
alarm condition(s). This parameter may be linked to other function blocks
that require a discrete input based on the detected alarm condition.
STD_DEV and CAP_STDDEV
Diagnostic parameters that can be used to determine the variability of the
process.