Emerson Filtering, Low Cutoff, Rosemount 3051S, Reference Manual, OUT mode in man, Fieldval

Rosemount 3051S

Reference Manual

00809-0200-4801, Rev BA April 2007

Filtering	The filtering feature changes the response time of the device to smooth
	variations in output readings caused by rapid changes in input. Adjust the
	filter time constant (in seconds) using the PV_FTIME parameter. Set the filter
	time constant to zero to disable the filter feature.

Figure 3-3. Analog Input

PV_FTIME filtering Diagram.

Low Cutoff

OUT (mode in man)

OUT (mode in auto)

PV

63% of Change

FIELD_VAL

Time (seconds)

PV_FTIME

When the converted input value is below the limit specified by the LOW_CUT parameter, and the Low Cutoff I/O option (IO_OPTS) is enabled (True), a value of zero is used for the converted value (PV). This option is useful to eliminate false readings when the differential pressure measurement is close to zero, and it may also be useful with zero-based measurement devices such as flowmeters.

NOTE

Low Cutoff is the only I/O option supported by the AI block. Set the I/O option in Manual or Out of Service mode only.

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