Emerson Rosemount OCX 8800, Instruction Manual

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Instruction Manual
IM-106-880C, OI
Section 7: Foundation
Fieldbus
April 2017
Application
Information
12
3
7.11.13 Application Information
The configuration of the AI function block and its associated output channels depends on the
specific application. A typical configuration for the AI block involves the following parameters:
Channel
If the device supports more than one measurement, verify that the selected channel contains
the appropriate measurement or derived value.
L_TYPE
Select Direct when the measurement is already in the engineering units that you want for the
block output.
Select Indirect when you want to convert the measured variable into another, for example,
pressure into level or flow into energy.
Select Indirect Square Root when the block I/O parameter value represents a flow measurement
made using differential pressure, and when square root extraction is not performed by the
transducer.
Scaling
XD_SCALE provides the range and units of the measurement and OUT_SCALE provides the
range and engineering units of the output.
7.11.14 Application Examples
Temperature Transmitter - Situation
A temperature transmitter with a range of –200 to 450°C.
Temperature Transmitter - Solution
Table 7-22 lists the appropriate configuration settings, and Figure 7-8 illustrates the
correct function block configuration.
Table 7-22 Analog Input Function Block Configuration for a Typical Temperature Transmitter
L_TYPE Direct
XD_SCALE Not Used
OUT_SCALE Not Used
Parameter Configured Values