18 Rockwell Automation Publication  1756-RM011A-EN-P - June 2016
Chapter 3 Hardware Specifications and Considerations
All 1756-IF6CIS channels are supplying loop power 
If all RTB VOUT-x terminals are used and all RTB RTN-x terminals are 
unused then all channels of the IF6CIS are supplying loop power, and there is 
no additional work required. 
One or more 1756-IF6CIS channels use external loop supply 
If one or more RTB VOUT-x terminals are unused and one or more RTB 
RTN-x terminals are used, then one or more of the IF6CIS channels has an 
external loop supply, and you must use the following format. 
If Floating Point Configuration: Communication Format is Float Data or CST Time Stamped 
Float Data
Set the ChxConfig.TenOhmOffset configuration tag to a non-zero value for 
each channel that uses an external loop power source. This tag was previously 
ignored by the 1756-IF6CIS module.