How do you assign units to an analog tag, Discrete tags, Example—square root scaling -28 – National Instruments BridgeVIEW User Manual

Page 86

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Chapter 3

Tag Configuration

BridgeVIEW User Manual

3-28

© National Instruments Corporation

Configure the tag for raw range from zero (Raw Zero Scale) to five
(Raw Full Scale). Select Linear, and set the engineering range from
50 (Eng Zero Scale) to 100 (Eng Full Scale).

Example

—

Square Root Scaling

A flow meter measures the flow rate of a liquid using a differential pressure
reading. The device server provides 4–20 mA readings. The actual flow is
measured in gallons per minutes (GPM). 4 mA corresponds to 0 GPM;
20 mA corresponds to 100 GPM.

Configure the tag for raw range from 4 (Raw Zero Scale) to 20 (Raw Full
Scale). Select Square Root Scaling and set the engineering range from
0 (Eng Zero Scale) to 100 (Eng Full Scale).

How Do You Assign Units to an Analog Tag?

Use the Engineering Unit ring to assign units to a tag. If the desired unit
is not in the list, select Enter New… and enter the desired unit. In the
previous example, you select units of GPM.

Discrete Tags

The only scaling available for discrete tags is invert scaling. Click the
Invert Data checkbox, shown in Figure 3-9 to advise the BridgeVIEW
Engine to invert the discrete value when it communicates with the
device server.

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