IEEE 1613 Compatible Substation Line Sharing Switch- TC Communications

Overview

A common application for substation meter polling is the use of a substation line sharing switch (SLSS).

An SLSS allows the sharing of phone lines between multiple devices using overdialling to select each part. A typical example of this is as follows:

Substation Line Sharing Switch Application Diagram

The SLSS allows the use of one phone line to select any of the devices by the polling computer, selecting them by overdialing an extension number assigned to the required device. This significantly reduces the number of dedicated phone lines required for the purpose of polling the remote devices. SLSS devices are typically designed with 8 ports. This application note describes a more flexible solution of 4-28 ports using a modern flexible design.

TC3848-1 4+1 Ch. VoIP+ with virtual PBX

The TC3848-1 has 1 FXO port coupled with 4 FXS ports

Used individually, the TC3848-1 has a virtual PBX to allow routing of the FXO port to one of the FXS ports.

The virtual PBX is fully configurable to allow the unit to be configured as a drop-in replacement for existing SLSS devices.

For a single unit there are the following packaging options

Port Expansion

To expand the number of ports, simply add more TC3848-1 units. For 8 ports, the configuration will look as follows:

In this configuration, the user can use one or both of the FXO ports as the virtual PBX allows either of the FXO ports to access any of the FXS ports.

Because of the flexibility of the TC3848-1, users may use this to share a single line to 8 or more ports. Alternatively, the FXO ports can be corrected to multiple polling locations for ultimate flexibility. Users may continue to add TC3848-1 up to at least 28 FXS ports by connecting the units via the included Ethernet port. Therefore, a 28 port SLSS will look as follows:

Again, although there are 7 TC3848-1, they all share the same virtual PBX, so any FXO ports can access any of the FXS ports. Mounting is flexible, up to and including, a 4U rack shown below.