beautypg.com

Rosemount 5300 series, Reference manual, Signal conversion – Emerson Process Management ROSEMOUNT 5300 User Manual

Page 311

background image

Reference Manual

00809-0100-4530, Rev BA
July 2009

J-5

Rosemount 5300 Series

SIGNAL CONVERSION

You can set the signal conversion type with the Linearization Type (L_TYPE)
parameter. You can view the converted signal (in percent of XD_SCALE)
through the FIELD_VAL parameter.

You can choose from direct or indirect signal conversion with the L_TYPE
parameter.

Direct

Direct signal conversion allows the signal to pass through the accessed
channel input value (or the simulated value when simulation is enabled).

Indirect

Indirect signal conversion converts the signal linearly to the accessed channel
input value (or the simulated value when simulation is enabled) from its
specified range (XD_SCALE) to the range and units of the PV and OUT
parameters (OUT_SCALE).

Indirect Square Root

Indirect Square Root signal conversion takes the square root of the value
computed with the indirect signal conversion and scales it to the range and
units of the PV and OUT parameters..

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. You can set the

I/O option in

Manual

or

Out of Service

mode only.

FIELD_VAL

100

Channel Value

EU*@0%

EU*@100%

EU*@0%

--------------------------------------------------------------------------------------------

=

* XD_SCALE values

PV

Channel Value

=

PV

FIELD_VAL

100

-------------------------------

EU**@100%

EU**@0%

 EU**@0%

+

=

** OUT_SCALE values

PV

FIELD_VAL

100

EU**@100%

EU**@0%

 EU**@0%

** OUT_SCALE values