Omega Vehicle Security OMP-MODL manual Shielded Twisted Pair Line

VDC-High Range Icon

3... INTERFACE MODULES

To minimize noise pickup on sensor wiring between the OMP-MODL and the end sensor or signal source, 18 to 22 AWG shielded, twisted pair wire is recommended.

Shielded Twisted
Pair Line	Terminal Strip
1	2	3	4	5	6	7	8	9	10	11	12

+

-

ml141

Shield

Figure 3... -15: VDC signal (and optional shield) terminal strip connection

FYI: Shielded wire minimizes the amount of noise picked up by the internal conductors carrying the signals by providing an `electrical shell’ or Faraday cage around the internal conductors.

Twisted pair wiring exposes both conductors equally to the ambient electrical noise. This common-mode type noise is easier to reject by the Interface Modules input signal conditioning circuitry than un-balanced (or differential) noise.

Shielding and/or twisted pair wire is especially recommended in electrically noisy environments for optimum signal protection. If shielded wire is used, a ground wire should be run from the MLAD-1 module Chassis Ground (terminal strip connection #16) to an earth ground connection to conduct away noise picked up by the thermocouple shield (Figure 2-8). Only one ground wire is required as all of the Shield terminal strip connections are interconnected within the logger and routed to the MLAD-1 Chassis Ground terminal.

NOTE: Do not ground the signal wiring shield conductor at the sensor end (the end away from the OMP-MODL) as this can induce additional noise into the sensor wiring..

3-26 USING THE OMP-MODL