Minimizing Interference

from Radiated Electrical

Noise

Important: Signals in this type of control system are very susceptible

to radiated electrical noise. The module is designed to set the loss-ofsensor

bit I:e.0/8 and the LDT-error bit I:e.0/0 when it detects position

values that are lost or corrupted by electrical noise.

Connect module output terminals to output devices with correct bonding:

• connect power supply output commons together

• electrically isolate power supply output commons from earth ground

• use bond wires that are equal in size to signal wires

Minimize interference from radiated electrical noise with correct

shielding and grounding:

• connect all of the following to earth ground:

– LDT flange, frame, and machine

– I/O chassis

– protective ground

– AC ground

– cable shields at one end only, preferably with 3/8” braid wire

(for analog output, ±15V dc PS, 24V dc PS, and LDT)

– terminal 4 of the input terminal block

• run shielded cables only in low-voltage conduit

• place the SLC-500 processor, power supply, and I/O chassis

assembly in a suitable enclosure