BusinessPhone Communication Platform 7.0
Facilities

## Key System Function

## Definition

A key system denotes a system in which all or selected trunks are directly represented on system telephones by means of external line keys.

## Use

The function is used when it is desired to employ all or parts of ASB 150 02 as a key system, so that extension users have a complete overview of the trunks belonging to the group.

### Grouping of trunks

The system can easily be divided into several mutually independent key-system groups.

Each trunk can be assigned to any key on any system telephone.

### Types of ring signals

An incoming call on a represented trunk can be given an optional type of ring signal:

- No ring signal
- Repeated ring signal
- Single ring signal
- Delayed repeated ring signal
- Delayed single ring signal

A typical example of use can be that those trunks that are foremost to be answered by the user are assigned a repeated ring signal whereas other trunks can be assigned a single delayed ring signal as indication that the call has not been answered by another extension. Other trunks can only be monitored and are not assigned any ring signal.

### Incoming DID calls

There are 2 possibilities how an incoming DID-call is presented on an external line key.

- No difference if the incoming call is a DID-call or not. (DID calls can also be picked up on the external line key.)
- Blocking the pick up functionality on the external line key in case of a DID call

## Operation

### DBC 211, DBC 222, DBC 212, DBC 631, DBC 223, DBC 213 and DBC 662 Telephones

#### Incoming calls

The call is signalled on all telephones on which the trunk is represented.

The line lamp flashes rapidly.

A ring signal is issued if this has been programmed for the key.

A call via a trunk is not shown on the display.

#### Answer

1. Press key for calling trunk.

- Associated lamp flashes to confirm connection.

If the answering telephone has a display, trunk number will be shown:

The group member who first presses the key for the calling trunk will receive the call.

On answer the corresponding keys on the other telephones in the group will glow steadily as indication that the trunk is busy.

#### Incoming DID calls

There is the possibility to block the pick up functionality on the external line key in case of a DID call.

This effects the situation when you want to pick up an incoming DID-call to a specific destination (extension, PBX-group, fictive number, ACD-group) by pressing an external line key. The LED of the external line key will show steady light instead. If the extension does not answer the call within the defined supervision time (command 1413) it will be automatically transfered to the rerouting position. Then it is possible again to pick up the call from the external line key, which is flashing since the call has been rerouted.

Example:

#### Outgoing calls

1. Press free external line key.

- (Key-lamp is extinguished).
- Caller receives external dial tone directly.

Extension user can now dial number of public network subscriber.

A telephone with display shows the dialled number:

#### Individual parking

1. Press external line key.

- Associated lamp flashes slowly.

The trunk line lamp flashes only on the telephone that parked the call.

The trunk can only be reaccessed from the extension who parked the call.

See also Parking – Individual (402/155 34-ASB 150 02 Uen).

#### Parking for general access

A special Hold key has to be programmed on each telephone which is to undertake this procedure.

1. Press Hold.

- Associated trunk line lamp flashes slowly.

The trunk line lamp flashes slowly on all telephones on which the trunk is represented.

The trunk can be reaccessed by any member of the group.

See also Parking For Common Access (401/155 34-ASB 150 02 Uen).

#### Disconnection

A call via a trunk is disconnected like a call via own line.

Normal voice mode:

1. Replace handset.

Handsfree mode:

1. Press Clear or On/Off.

## Capacity

The system can be programmed for an optional number of key-system groups.

The number of trunks in each group is limited only by the number of available programmable keys on the system telephones.

DBC 220 |  | = 4 |  |  |
DBC 222 |  | = 4 |  |  |
DBC 223 |  | = 4 |  |  |
KEY PANEL |  | = 17 |  |  |
Old telephones:
DBC 210 |  | = 3 |  |  |
DBC 211 |  | = 4 |  |  |
DBC 601 |  | = 0 |  |  |
DBC 212 |  | = 4 |  |  |
DBC 631 |  | = 10 |  |  |
DBC 213 |  | = 14 |  |  |
DBC 662 |  | = 30 |  |  |
KEY PANEL |  | = 17 |  |  |

## Limitations

A programmed external line key always shows the status of the trunk even if, for example, during night service the line has a programmed answering position.

Consequently, calls on the line can always be answered by depression of the key.

Even if the trunk is represented on a key it can always be called by means of its individual directory number, provided this is known.

## Programming

It is a prerequisite for the creation of a key-system is that all trunks included in the group are to be assigned their own programmable keys.

All extensions in the group possessing system telephones are then assigned the same external line keys with the aid of the copying command.

For the copying function, see Facility Description (155 34-ASB 150 02 Uen).

0301 |  | Key function

Enter function = 12.

0302 |  | Number/ID

0303 |  | Ringing alternative

### Individual programming

The keys can also be programmed via individual programming.

See Facility Description (155 34-ASB 150 02 Uen).

0301 |  | Key function

Enter function = 35

Following command is only accessable via BMS:

1031 |  | Answer by external line key allowed?

## Equipment

All members of a key-system must possess DBC 211, DBC 222, DBC 212, DBC 631, DBC 223, DBC 213 or DBC 662 Telephones.

Revision: E © Ericsson Enterprise 2005