Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 93)

1 Publication 1746-UM003A-EN-P
Chapter
7
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 5 to set up one channel for operation. The module operates in Class 1
mode for this sample. This setup is then used in a typical application to display
temperature.
The supplementary example demonstrates how to perform a dynamic
configuration of all eight 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. The module operates in Class 3 operation in
order to support the scaling and status.
Basic Example The following illustration 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 7.1 Device Configuration
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
•
28 Hz input filter
•
1.0 mA excitation current
SLC 5/04
1746-OB16
1746-NR8
LED Display
(DC Sinking Inputs, BCD Format)
Bath
200
Ω
Platinum RTD