Rockwell Automation 1771-OFE/B Analog Output Module User Manual - Manual (Page 24)

2-10
Publication 1771Ć6.5.30 - November 1998
The module requires shielded cable for signal transmission to the
analog devices. Use Belden 8761 shielded cable, which consists of a
single insulated, twisted-pair of conductors, covered along their
entire length by a foil shield and encased in plastic. The shield
reduces the effect of induced noise at any point along the cable.
You must ground the shield at the chassis end only. We recommend
connecting each output cable’s shield to a properly grounded
common bus. Refer to “Industrial Automation Wiring and Grounding
Guidelines for Noise Immunity,” publication 1770-4.1, for additional
information.
Figure 2.6
Cable Grounding
Remove a length of cable
jacket from the Belden 8761
cable.
Pull the foil shield and bare
drain wire from the insulated
wires.
Bare drain
wire
Insulated
wires
Foil
shield
Twist the foil shield and drain
wire together to form a single
strand.
Attach a ground lug.
20104
Belden 8761 Cable
19480
Grounding Stud
1 Use the cup washer if crimpĆon lugs are not used.
Chassis Ground
Ground Lug
Ground Lug 1
Star
Washer
I/O Chassis
Side Plate
Nut and Captive
Washer
ExternalĆtooth
Washers
#10 ThreadĆforming screw
19923
Shield and Drain
twisted together
Shield and Drain
twisted together
SingleĆpoint Grounding
Extend shield to termination point.
Expose just enough cable to adequately terminate inner conductors.
Use heat shrink tubing or
other suitable insulation
where wire exits cable
jacket.
Nut
When you connect grounding conductors to the I/O chassis
grounding stud, place a star washer under the first lug, then
place a nut with captive lock washer on top of each ground lug.
Ground the Chassis and
Module