Owner's manual

Appendix
A-1
A Applications
ANALOG INPUT (AI)
FUNCTION BLOCK
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.
Application Example:
Temperature Transmitter
Situation A temperature transmitter with a range of –200 to 450 °C.
Solution Table A-1 lists the appropriate configuration settings, and Figure A-1
illustrates the correct function block configuration.
.
Figure A-1. Analog Input Function
Block Diagram for a Typical
Temperature Transmitter.
TABLE A-1. Analog Input Function Block Configuration for
a Typical Temperature Transmitter
Parameter Configured Values
L_TYPE Direct
XD_SCALE Not Used
OUT_SCALE Not Used
Temperature
Measurement
To Another
Function Block
OUT_D
OUT
AI Function Block
FIELDBUS-FBUS_04A