Several specific steps can be taken to help reduce the effects of environmental
noise on analog signals:
• install the MicroLogix 1100 system in a properly rated (i.e., NEMA)
enclosure. Make sure that the MicroLogix 1100 system is properly grounded.
• use Belden cable #8761 for wiring the analog channels, making sure that the
drain wire and foil shield are properly earth grounded.
• route the Belden cable separately from any ac wiring. Additional noise
immunity can be obtained by routing the cables in grounded conduit.
Grounding Your Analog Cable
Use shielded communication
cable (Belden #8761). The
Belden cable has two signal
wires (black and clear), one
drain wire, and a foil shield.
The drain wire and foil shield
must be grounded at one end
of the cable.
IMPORTANT
Insulation
Do not ground the drain wire and foil shield at both ends of
the cable.
MicroLogix™ 1100 Programmable Controllers
Foil Shield
Publication 1763-IN001A-MU-P - May 2005
Black Wire
Clear Wire
Drain Wire
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