Flowserve Logix MD+ ValveSight - Manual (Page 111)

ValveSight™ Diagnostics DTM Manual for Logix MD+ Positioner with HART®
FCD- LGENSF0014-00
© Flowserve Corporation
111
Deviation
The Deviation Page allows you to view and set limits related to the Deviation Alarm.
Deviation is a comparison between the current position of the valve and the final
command signal. If the difference exceeds the tolerable error limit for longer than the
deviation time frame selected, then the alarm is activated. (See the example illustration
below.) The final command signal may be different than the input 4-20 mA input command
if a Characterization Curve, Tight Shutoff Limit, or Soft Stop Limit is applied.
Status Area
The Active Indicator area shows the status of the most relevant active indicator. The color
of the "LED light" corresponds to the Active Indicator and the first color of the blink code
sequence on the positioner. Generally green indicates no immediate issues. Yellow
indicates a developing issue. Red indicates the ability to control may be compromised. A
detailed list of the indicators is given in the
Alarm Congfiguraion - Alarm Annunicator page.
The Command Source field indicates weather the positioner is being controlled by digital or
an analog (4-20 mA) command source.
Deviation Histogram
The graph displays a histogram with current values and a histogram with data gathered
during the training period. This is an easy way to see the range of typical values to set
meaningful warning and alarm limits. It is also helpful to see how the data may have shifted
since the training period. The histogram is frequently updated when the positioner is in
operation.