Rockwell Automation 1771-IFE/C INSTL.INSTRUCTIONS ANALOG INPU - Manual (Page 6)

Analog Input Module 6
Publication 1771Ć5.45 - July 1997
Connect your I/O devices to the cat. no. 1771-WG wiring arm
shipped with the module.
!
ATTENTION: Remove power from the 1771 I/O
chassis backplane and field wiring arm before
removing or installing an I/O module.
•
Failure to remove power from the backplane or
wiring arm could cause module damage, degradation
of performance, or injury.
•
Failure to remove power from the backplane could
cause injury or equipment damage due to possible
unexpected operation.
Input connections for the 1771-IFE module with:
•
single-ended inputs are shown on page 7
•
differential inputs are shown on page 8
Minimizing Ground Loops
To minimize ground-loop currents on input circuits:
•
use single-ended mode whenever possible
•
use 2-wire transmitters with a common power supply
•
separate 2-wire and 4-wire transmitters between different
modules
•
tie 4-wire transmitter and/or separate power supply grounds
together
Important: We do not recommend mixing 2-wire and 4-wire
transmitter inputs on the same module. Power supply
placement can make it impossible to eliminate ground
loops.
Cable Lengths
Recommended maximum cable length for voltage-mode input
devices is 50 feet. This recommendation is based on considerations
of signal degradation and electrical noise immunity in typical
industrial environments. Cable length for current-mode input
devices need not be as restrictive because analog signals from these
devices are less sensitive to electrical noise interference.
Connect Wiring to the
Field Wiring Arm