Exchange Dial Tone:

The dial tone is a continuous sound which lasts for 8 seconds during which the exchange waits for dialling to be initiated. If no dialling takes place during this period the EPABX times the user out and starts issuing a busy tone.

P and T Dial Tone:

On accessing a direct line, you will obtain the normal P and T Dial tone.

Busy Tone:

The busy tone is a discontinuous sound (Du-....Du).The busy tone consists of equal duration ON and OFF signals. This tone indicates that the system is too busy to accept any operation or encountered when the called number is busy.

Internal Ring Tone:

This is a discontinuous sound of two frequencies and sounds like Durrrr .. for one second with a two second silence interval. When you dial extensions, you will hear this ring-back tone till the extension answers.

Ringing Tone:

Five types of rings can be heard from the telephone instrument connected to the System.
When your instrument is called by another internal non executive extension the ring will be a continuous one with a one second ON and two seconds OFF period. While from Executive extension it will be two short cadence followed by long cadence.
A ring from a CO.Jn.(Trunk)Line will ring like a normal telephone for Non-STD calls and for STD calls it will be two long cadence followed by short cadence.
When the extension is enabled to receive CLID, it will get a short ring followed by CLID numbers and a short ring, after that depending upon call it will ring as per above four cadence.

Feature Tone:

A tone (trin-trin) is heard after a Hook Flash indicating that the system is in the "feature" mode.

In-Coming Call Queuing Tone:

This tone will be heard when a caller is waiting for your extension to get free. It is similar to the feature mode tone and will be heard repeatedly with a long pause. This tone will be heard only when there is a CO.Jn.(Trunk) incoming call.

Intrusion Tone(Barge in Tone):

This is a fast beep.

Hook Flash (HF):

The features of your EPABX require the use of a Hook Flash (HF). This is performed by tapping the hook switch of your extension for a period of less than Flash time setted for that extension. Care should be taken not to press the hook switch for more than Flash time when a HF is desired. If the exchange hook switch is pressed for longer than flash time, it will register a "hang up" or "reset". When disconnection is desired care should be taken to press cradle exceeding Flash time or otherwise call will go on Hold and feature tone will be heard (this happens most times when dialed number on CO. is busy and one tries again dialing same number by disconnecting and accessing CO. dials same number so disconnect properly).
Note: Some telephone instruments have a built in electronic flash key. It is advisable to use the flash key instead of the hook switch in order to register a "hook flash".