There is a connector made by Tyco/AMP that is similar to the RJ31X but it has shorting bars in different pins. This one is AMP part number 557789-1. The little diagram below shows the location of the shorting bars.


You can get this connector from Digikey (P/N A24914-ND). And yes they have them in stock.

Here is a link to the specification drawing for the connector.

As a note of interest, this type jack is called an RJ48X and is deployed in T1 phone line installations. It permits a T1 line to be daisy chained down to a series of jacks in a facility. Then one can come along and plug in some type of T1 line termination equipment such as a MUX or ROUTER and and have connection to the network. All other devices downwing become disconnected.....Very similar to the way the RJ31X works for the security system application. Here are some links that will provide more information about RJ48X connectors.

RJ48C, RJ48S, RJ48X - T1 Jacks

LEVITON Voice & Data App Notes and Installation Guide.

<big>Michael Karas</big>