Rockwell Automation Publication  1756-RM011A-EN-P - June 2016 17
Hardware Specifications and Considerations Chapter 3
In general, if in the 6-channel module RPI is less than RTS, adjustments can be 
made in the 6-channel Emulation module configuration to achieve the same 
performance. Keep in mind that if RPI is less than RTS your performance in 
Emulation mode is faster than it was as a 6-channel module. 
In general, if in the 6-channel module RPI is greater than RTS then no 
adjustments are necessary in the 6-channel Emulation module configuration to 
achieve the same performance. 
Cold Junction Compensation 
on Thermocouple Modules
ControlLogix® thermocouple modules use cold junction compensation (CJC) 
sensors. You must order the senors separately by ordering catalog number 
1756-CJC, which consists of two CJC jumpers.
All CJCs for all 1756 Rockwell Automation® thermocouple modules are 
electrically the same. The modules use a precision thermistor, but not all CJCs 
can physically fit in all RTBs so you cannot substitute different CJCs from 
different modules. 
If you are using a 1756-IT6I or 1756-IT6I2 module with thermocouples and 
are not using Remote CJC Compensation, be sure to order a 1756-CJC sensor 
for the 1756-IRT8I RTB. The1771 thermocouple modules do not always use a 
CJC resistor that is electrically compatible with 1756 modules. 
Using an External Loop 
Supply with the 
1756-IF6CIS Module
The 1756-IF6CIS module can be used to supply loop power to an end device. 
The module can simplify wiring and reduce the cost of installation by 
eliminating the need for an external loop supply. While the 1756-IF6CIS 
module typical case can be to supply loop power, the 1756-IF6CIS module can 
still be used with an external loop supply on one or more channels. If one or 
more of your 1756-IF6CIS channels uses an external loop supply, then you 
must add some additional logic to your program to accommodate those 
channels with an external loop supply. 
IMPORTANT If you change the RPI of an 8-channel module on a ControlNet network, you 
need to reschedule the network, which requires that the process be placed in 
Program mode.