Emerson Rosemount 3051 CF Series, Reference Manual

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transmitter can generate an alert. The Process Intelligence performs its statistical
processing on the pressure measurement of the field device. The statistical values are also
available as secondary variables from the transmitter via AI Function Blocks if a user is
interested in their own analysis or generating their own alarms.
7.3 PIL diagnostics
The Advanced Diagnostics Suite also implements a Plugged Impulse Line (PIL) detection
algorithm. PIL leverages Process Intelligence technology and adds some additional
features that apply Process Intelligence to directly detect plugging in pressure
measurement impulse lines. In addition to detecting a change in the process noise
signature, the PIL also provides the ability to automatically relearn new baseline values if
the process condition changes. When PIL detects a plug, a “Plugged Impulse Line
Detected” Plantweb
™
alert is generated. Optionally, the user can configure the PIL to,
when a plugged impulse line is detected, change the pressure measurement status quality
to “Uncertain” to alert an operator that the pressure reading may not be reliable.
Important
Running the Advanced Diagnostics Block could affect other block execution times. We
recommend the device be configured as a basic device versus a Link Master device if this is
a concern.
7.4 Process Intelligence technology
Emerson has developed a unique technology, Process Intelligence, which provides a
means for early detection of abnormal situations in a process environment. The
technology is based on the premise that virtually all dynamic processes have a unique
noise or variation signature when operating normally. Changes in these signatures may
signal that a significant change will occur or has occurred in the process, process
equipment, or transmitter installation. For example, the noise source may be equipment
in the process, such as a pump or agitator, the natural variation in the DP value caused by
turbulent flow, or a combination of both.
The sensing of the unique signature begins with the combination of a high speed sensing
device to compute statistical parameters that characterize and quantify the noise or
variation. These statistical parameters are the mean and standard deviation of the input
pressure. Emerson provides filtering capability to separate slow changes in the process
due to setpoint changes from the process noise or variation of interest.
Figure 7-2 shows
an example of how the standard deviation value ( s ) is affected by changes in noise level
while the mean or average value ( m ) remains constant. The device calculates statistical
parameters on a parallel software path to the path used to filter and compute the primary
output signal (e.g., the pressure measurement used for control and operations). The
primary output is not affected in any way by this additional capability.
Advanced pressure diagnostics Reference Manual
July 2020 00809-0100-4774
120 Rosemount 3051