FAQ:Cab Bus Connectors

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The NCE Cab Bus can use a DIN Plug, a TRS Phone plug, or an RJ–12 plug.

DIN Plug

Using a 5 pin 180º DIN connector. From the left, with keyway at the bottom, going clockwise:

  1. +12 Volts (nominal)
  2. Ground
  3. "A" lead of RS-485 signal
  4. "B" lead of RS-485 signal

This is optional, can be used when wired for compatibility with the Lenz XpressNet

Three Pin (TRS) Phone Plug

  • Tip: +12 Volts (7.5 to 16 Volts DC is OK)
  • Ring: RS-485 "A" lead
  • Sleeve: Ground


Main article: Modular Connector

This connection is used for the Cab Bus. The UTP (Utility Throttle Panel) has these connections.

  1. Reserved
  2. +12 VDC
  3. A lead of RS-485 signal
  4. B lead of RS-485 signal
  5. Ground
  6. Reserved

Only the 4 inner wires are used. This is the preferred interface.

Cable Identification

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Three types of Cab Bus connections
  1. Cab Bus Cable with RJ12 connector 6P6C. A flat 6-wire cable is used for tethered cabs, UTP panels, the cab bus, and the Power Cab[1][2]. For regular cabs, the maximum length is 40 feet. The two outer wires (white and blue) on the six-wire cable provide the track power output of the Power Cab. In other applications the two outer wires are not used, including using it for the Cab Bus, RB02, and the direct connection between the RB02 and RPT1.
  2. Cab Bus Cable with RJ12 connector 6P4C. A 4-wire coiled cable 6 feet long is used for tethered cabs. Notice the 6-pin connector with only 4 slots being used. This is a regular coiled Cab cable. No track power. One length only,
  3. Control Bus Booster Data Cable with RJ-H connector 4P4C. A 4-wire cable is used between boosters and a command station. Maximum length is 300 feet.
  4. Clean Data is required on pins 3 and 4 for reliability.

It is very important to get the correct type of cable. Using a cable which flips connections will damage your equipment.

  1. When used with the Power Cab, this cable carries full track power. The maximum length is 7 feet in this application.
  2. The Power Cab specific cable has heavier wires for wires 1 and 6. Replacements should be purchased directly from NCE.