System overview, System operation, System overview -7 – Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual User Manual
Page 17: System operation -7
Publication 1746-UM003A-EN-P
Overview 1-7
System Overview
Figure 1.3 RTD Configuration
Each individual channel on the RTD module can receive input signals from 2,
3 or 4-wire RTD sensors or from resistance input devices. You configure each
channel to accept either input. When configured for RTD input types, the
module converts the RTD readings into linearized, digital temperature
readings in °C or °F. When configured for resistance inputs, the module
provides a linear resistance value in ohms.
System Operation
The RTD module has 3 operational states:
•
power-up
•
module operation
•
error (module error and channel error)
IMPORTANT
The RTD module is designed to accept input from RTD
sensors with up to 3 wires. When using 4-wire RTD
sensors, one of the 2 lead compensation wires is not used
and the 4-wire sensor is treated like a 3-wire sensor. Lead
wire compensation is provided via the third wire. Refer
to Wiring Considerations on page 2-8 for more
information.
RTD Modules
SLC Processor