Application Examples; Basic Example - Allen-Bradley SLC 500 1746-NR4 User Manual

Basic Example

Application Examples

This chapter provides two application examples to help you use the RTD
input module. They are defined as a:
basic example
supplementary example
The basic example builds on the configuration word programming provided
in chapter 6 to set up one channel for operation. This setup is then used in a
typical application to display temperature.
The supplementary example demonstrates how to perform a dynamic
configuration of all four channels. The example sets up an application that
allows you to manually select whether the displayed RTD input data for any
channel is expressed in C or F.
Use the worksheet in Figure 8.2.
Figure 8.1 indicates the temperature of a bath on an LED display. The
display requires binary coded decimal (BCD) data, so the program must
convert the temperature reading from the RTD module to BCD before
sending it to the display. This application displays the temperature in F.
Figure 8.1
Device Configuration
SLC 5/04
LED Display
(DC Sinking Inputs, BCD Format)
Channel Configuration
Configure the RTD channel with the following setup:
200 Ω Platinum RTD
F in whole degrees
zero data word in the event of an open or short circuit
10 Hz input filter
2.0 mA excitation current
Chapter
8
1746–OB16
1746–NR4
200 Ω Platinum RTD
Bath
8–1