Rockwell Automation 1769-IF4FXOF2F Compact Combination Fast Analog I/O Module - Manual (Page 21)

Publication 1769-UM019A-EN-P - October 2008 21
Installation and Wiring Chapter 2
System Wiring Guidelines Consider the following when wiring your system:
•
All module commons (ANLG Com) are connected in the analog
module.
•
The analog common (ANLG Com) is not connected to earth
ground inside the module.
•
Channels are not isolated from each other.
•
For optimum accuracy, limit overall cable impedance by
keeping your cable as short as possible. Locate the I/O system
as close to your sensors or actuators as your application will
permit.
•
Use Belden 8761, or equivalent, shielded wire.
•
Under normal conditions, the drain wire and shield junction
must be connected to earth ground via a panel or DIN rail
mounting screw at the analog I/O module end.
(1)
Keep shield
connection to ground as short as possible.
•
If multiple power supplies are used with analog inputs, the
power supply commons must be connected.
•
The module does not provide loop power for analog inputs. Use
a Class 2 power supply that matches the input transmitter
specifications.
•
Differential analog inputs are more immune to noise than
single-ended analog inputs.
•
Voltage outputs (Vout 0+ and Vout 1+) of the 1769-IF4FXOF2F
module are referenced to ANLG Com. Load resistance for a
voltage output channel must be equal to or greater than 1 k
Ω
.
•
Current outputs (Iout 0+ and Iout 1+) of the 1769-IF4FXOF2F
module source current that returns to ANLG Com. Load
resistance for a current output channel must remain between 0
and 500
Ω
.
•
Voltages on Vin+, V/Iin-, and Iin+ terminals of the
1769-IF4FXOF2F module must be within ±10V DC of analog
common (ANLG Com).
(1) In environments where high-frequency noise may be present, it may be necessary to directly ground cable
shields to earth at the module end and via a 0.1 µF capacitor at the sensor end.