Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 136)

136 Publication 1756-UM009C-EN-P - December 2010
Chapter 6 Temperature-measuring Analog Modules (1756-IR6I, 1756-IT6I, and 1756-IT6I2)
Use Module Block and
Input Circuit Diagrams This section shows the 1756-IR6I, 1756-IT6I and 1756-IT6I2 modules’ block
diagrams and input circuit diagrams.
1756-IR6I, 1756-IT6I and 1756-IT6I2 Module Block Diagram
DC-DC
Converter
A/D Converter
RIUP
Circuit
43499
DC-DC
Converter
Vref
Optos
Micro-
controller Backplane
ASIC
Serial
EEPROM
FLASH
ROM
SRAM
System
+5V
Field Side Backplane Side
DC-DC
Shutdown
Circuit
Vref
A/D converter
Optos
Isolated
Power
Details of the RTD
and Thermocouple
input circuitry are
shown on
page 137 .
Vref
A/D Converter
Temperature-sensing
Device
Channel 0
Channel 1
Cold Junction
Compensation
channel
IMPORTANT: The cold junction compensation (CJC) channel
is used on Thermocouple modules only. The
1756-IT6I module has one CJC channel, and
the 1756-IT6I2 module has two CJC channels.
This diagram shows two channels. There are six channels on the temperature-measuring modules.
= Channel Isolation
Isolated
Power