Rosemount 8712C - Maximum Percent Limit; Time Limit; Review Variables; Review

4-15
Device Software Functions
Maximum Percent Limit
0 to 100 Percent
The maximum percent limit is a tolerance band set up on either side of
the running average. The percentage value refers to deviation from the
running average. For example, if the running average is 100 gal/min,
and a 2 percent maximum limit is selected, then the acceptable range is
from 98 to 102 gal/min.
Values within the limit are accepted while values outside the limit are
analyzed to determine if they are a noise spike or an actual flow change.
Time Limit
0 to 256 Seconds
The time limit parameter forces the output and running average
values to the new value of an actual flow rate change that is outside
the percent limit boundaries. It thereby limits response time to flow
changes to the time limit value rather than the length of the running
average.
For example, if the number of samples selected is 120, then the
response time of the system is 10 seconds. In some cases this may be
unacceptable. By setting the time limit, you can force the Model
8712C/U/H to clear the value of the running average and re-establish
the output and average at the new flow rate once the time limit has
elapsed. This parameter limits the response time added to the loop. A
suggested time limit value of two seconds is a good starting point for
most applicable process fluids. The selected signal processing
configuration may be turned ON or OFF to suit your needs.
REVIEW VARIABLES
The Model 8712C/U/H includes a capability that enables you to review
the configuration variable settings.
Review
The flowmeter configuration parameters set at the factory should be
reviewed to ensure accuracy and compatibility with your particular
application of the flowmeter.
NOTE
If you are using the LOI to review variables, each variable must be
accessed as if you were going to change its setting. The value displayed
on the LOI screen is the configured value of the variable.
HART Fast Keys 1, 4, 4, 6
LOI Key Aux. Function
HART Fast Keys 1, 4, 4, 7
LOI Key Aux. Function
HART Fast Keys 1, 5