Rockwell Automation 1756-OF8I ControlLogix Eight-channel Isolated Analog I/O Modules - Manual (Page 144)

144 Rockwell Automation Publication 1756-UM540A-EN-P - May 2014
Chapter 8 Calibrate the ControlLogix Isolated Analog I/O Modules
Calibrate the 1756-IRT8I Module
You can calibrate the 1756-IRT8I module for use with the following input types:
• RTD (Ohms) - 3 and 4 Wire types
• Thermocouple (mV)
Calibrate the 1756-IRT8I Module for an RTD Input Type
The 1756-IRT8I uses two precision resistors to calibrate the channels in ohms.
You connect the following:
• 1
Ω
precision resistor for low reference calibration
• 487
Ω
precision resistor for high reference calibration
The 1756-IRT8I module can operate in multiple input ranges when an RTD is
connected. However, the module calibrates only in the 1…510
Ω
range.
Follow these steps to calibrate your module.
1. Go online with your project.
2. Right-click the module you want to calibrate and choose Properties.
IMPORTANT After you connect either precision resistors, we recommend that you
wait for a minimum of two minutes before proceeding to the next task
to obtain the highest calibration accuracy.
For more information, see page 146 and page 147 .
IMPORTANT When you are wiring precision resistors for calibration, follow the wiring
example on
page 89 . Make sure terminals IN_x(-)/B and IN_x/RTD C are
shorted together at the RTB.
You can calibrate the module for 3-wire or 4-wire mode. Calibrate in the
mode in which the module operates.