RJ31X

Purpose:

The RJ31x connector is the international standard connector for enabling what is known in Australia as "Mode 3" connection for alarm circuits

Electrical Network Connection:

One pair in from exchange, one pair out to in-house wiring. Series tip and ring connections provide seizure or exclusion service delivering dial tone to a the alarm panel while excluding, or electrically disconnecting all other devices connected in-house.

Mechanical Arrangement:

The incoming line from exchange is connected to pins 4 and 5 of the RJ31X socket. The in-house wiring is connected to pins 1 and 8 of the socket. An 8 position, 8 contact (8P8C) non keyed miniature jack assembly which conforms to Telstra specifications, is fitted with shorting bars which return circuits to bridged service when the mating 8 position modular plug is removed.

Typical Usage:

Commonly used with burglar and fire alarm equipment that uses the telephone line to dial out to an emergency service or other nominated telephone number.

To assure seizure when required, the line is connected in series by the RJ31X. From there, tip and ring pass into the alarm equipment where a relay or other device decides whether the dial tone will go back out to the in-house wiring (on T1 and R1), or seized for use by the alarm.

Any network interface jack that can allow a connected device to disrupt basic telephone service to other devices because of its wiring configuration (for example, by running tip and ring through a relay) must have a provision to automatically return service to the other locations if the seizing device (the alarm unit) malfunctions or is removed.

This is accomplished, when the alarm panel plug is removed, with shorting bars. Gold plated metal tabs inside the RJ31X device will provide direct connection of tip and ring back to the other locations when the miniature 8 position plug is removed from the jack. Inserting the plug lifts the gold plated contact wires away from the shorting bars. and extends the tip and ring circuit to the series leads going into the alarm device.

Purpose:

The RJ31x connector is the international standard connector for enabling what is known in Australia as "Mode 3" connection for alarm circuits

Anti Tamper:

There is provision for installation in "Anti Tamper" mode. In this mode the alarm will be activated if the alarm panel plug is removed from its socket, or if the line is cut between the alarm panel and the RJ31X socket.

Where the alarm Panel utilises it, tamper protection is enabled by connecting pin 2 to pin 7.

Advantages:

The main advantages of using the RJ31X for Mode 3 installation are that it is Telstra compliant, meets the International Standard, is simple to install, and is compatible with other devices, such as Central Filters and ADSL Alarm filters.