British Telecommunications (BT) MINIMASTER 1, Руководство пользователя

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Intercom calls are secret from the exchange line and no extension can gain access
to the intercom circuit when it is in use, unless invited to join a conference.
The intercom circuit releases as soon as either user replaces the handset (first
party clear). The intercom circuit is "timed-out" (released) if the caller does not dial
within 10 seconds of receiving intercom dial tone. The circuit is then available for another
call.
Outgoing Exchange Calls.
To make an outgoing exchange line call, lift the handset and on receipt of system
dial tone dial digit
9.
If the exchange line is free it will be connected and exchange dial
tone will be received. If the exchange line is busy no tone will be heard after dialling '9'.
When exchange dial tone is received, dial the required code and number. The required number
should be dialled without pausing. A pause or delay may result in the call being inadvert-
ently transferred. If a barred code has been dialled the caller will receive no tone, the
exchange line will be released by the CCU and will be available should another extension
make an exchange line call.
Incoming Exchange Calls.
An incoming call is detected by the
CCU
and system ringing is connected to the
extension according to the selected ringing programmes. Any extension may answer
the incoming call, if the extension is ringing, lift the handset, the call is connected auto­
matically. If the extension is not ringing lift the handset and dial digit '8', the call will
then be connected to the extension.
Hold and Transfer.
An exchange I ine call may be held by either:
a. dialling your own extension number. The exchange line will be held
and the extension handset may be replaced. The CCU will ring
the holding extension once every 20 seconds to remind it that the
exchange line is being held. The extension may return to the exchange
line by lifting the handset and dialling digit 7. Similarly any extension
may access the exchange line by dialling '7'.
b. dialling another extension number. The exchange line will be held and
an intercom enquiry call made to another extension. This enquiry call
is secret from the exchange line. Either extension can gain access to the
held exchange line by replacing the handset momentarily, and on lifting
the handset dialling digit '7'. If the intercom circuit is already in use
when an exchange call is to be held, dialling an extension number will
result in no tone being received. To return to the exchange line the
holding extension replaces the handset momentarily and on relifting
the handset dials digit '7'.
9.