BusinessPhone Communication Platform 4.0
System Description ASB 150 02

## Support Functions For I/Os

### Character set

The PBX works internally with one character set that consists of an alphabet that is adapted for the character windows on Ericsson digital system telephones. The character set is to a large extent compatible with the "US ASCII character set", complemented with national characters for those markets for which the PBX is adapted.

When texts, etc. are to be presented on an external medium, the internal character set will be converted into a character set that is compatible with the peripheral unit.

### V.24 ports (RS 485)

The V.24 ports for connecting external units (computers, printers) are located on the CPU-D_ and AUX_-boards.

The speed of the character transmission is programmable per port. As regards to other parameters, commands exist that select the type of equipment that the board is connected to. This is the basis for the setting of all other parameters (number of bits, parity, etc.) including line-protocol (if any). Furthermore, commands that state whether our internal character set shall be converted to/from the connected equipment are supplied.

External modems can be connected to the ports. For "HAYES"-type modems certain programmable parameters are provided that are transferred to the modem when the port is connected.

On the CPU-D4 board one port is configurable for RS485 bi-directional serial data operation. This data equipment can be connected up to 1200 m from the exchange.

### Built-in modem

The CPU-D4 board supports data transfer up to 14.kbd using its V.32bis-modem. The modem is connected to the internal PCM-bus and is primarily intended for the remotely-connected operation & maintenance system of the PBX. This applies also for the Cordless System Manager (CSM) software. Remote maintenance of the cordless system is supervised and carried out via the CPU-D4. Thus, O&M-system RASC or CSM can communicate with the PBX via a connection established via the public network.

Revision: K © Ericsson Enterprise 2003