Telco Splitters


1) Why use a Telco Splitter?
2) What does a Telco Splitter do and look like?
3) What is a compatible Splitter?  Selection Guide.
4) Good and Bad Examples.

With the exception of the discontinued CS01 command station and the PowerCab, all NCE command stations should take advantage of Cab bus splitter.  To learn more, go here:NCE Command Stations

1) Why use a Telco Splitter?

The Telco Splitter is optional.  Using one can lead to potenially better Cab bus electrical performance and/or more flexible installation.  If you place the Command Station in the middle of your Cab Bus run length wise, then the physical distance between the Command Station to any one end of the cab bus is cut in half.  If the wire run has been cut in half, then the voltage drop for both the signals and power is also cut in half.  

Note: In NCE's first command station called the CS01, it offered a built-in "Splitter" capability.  Hence purchasing a telco splitter for the current NCE command station(s) simply restores that lost capability.

2) What does a Telco Splitter do and look like?

A telco splitter is device that electrically takes a single plug input and divides it up or "Splits" it into multiple jacks to allow more things to share a connection.

Here is a diagram to give you an idea of what a 2 way splitter looks like in a phone installation.  For us, we are talking cab bus panels or radio base station connection.

Splitters come in two physical plug formats as well as be a 2 way or 3 way type.

1)  Two way splitter with a cord for the plug end.

The advantage of this type is that it allows you to do the split away from the front panel of the command station keeping it fully visible.  Full access to control bus jack is maintained.


2) Two way splitter with plug on the back.

The advantage of this type is that it simpler and potentially cheaper.   However it can block access to the Control Bus Jack.  You will have to make the Control Bus cable connection first and then install the splitter.

3) What is a compatible Splitter?

All phone splitters will work for phones, but that not necessarily true for the Cab Bus.  The NCE Telco Cab bus wiring requires a Pin to Pin connection system.  Phone systems do not.

Unfortunately there is no way to know by description if a given splitter will work.  Retailers do not use consistent phone line terminology.  
The correct phone line name is "RJ14 2 way splitter"  RJ14 refers to 4 wires or connections. 

From a Modular Connector description point of view, we want 6P4C 2 way splitter.

To learn more about what RJ means or about modular connector designations, go here: Telco RJ?


A splitter will work if it has:

1) 4 or 6 gold contacts on ALL of it ports (plugs and jacks).

2) No specific names or designations on any given port.

BAD:  Avoid any splitter if it has:

1) just 2 gold contacts on ANY of it ports.

2) a specific name or the word or word to describe any port.

4) Good and Bad examples:

BEST:  This is a RJ14 2 way splitter.  Notice no names per jack and there are 4 gold contacts in each jack.

GOOD:  This is a RJ14 3 way splitter.  Notice no names per jack and there are 4 gold contacts in each jack.  

This splitter is technically not as good as the 2-way shown above for it splits the bus into 3 segments.  The NCE cab bus uses a industry standard communication bus called RS-485.   The standard requires the bus to be a single long linear daisy chain bus from end to end. Any stub of this linear bus must be kept short as possible as in no long then the length of a standard throttle/cab cable (7 or so feet). Hence "By The Book" the use of a 3-way to create 3 long cab bus runs would violate the Cab Bus specifications regarding RS-485 rules.  However if you use the 3rd port to to act as a test jack for a cab or have it feed a RB02 radio based station that is less than 7 or so feet away, then this is acceptable.

BAD: This 2 way splitter has names associated with each port.  Also notice it does not have 4 gold contracts.  It only has 2 per jack.

BAD:  This 3 way splitter has specific names on it's ports.