i.1
Introduction
The
2+8
is a microprocessor-controlled Hybrid Keysystem/PABX. See
Figure
1.1.
It has an ultimate capacity for two exchange lines and eight
extensions. The
2+8
is supplied complete as a
2+8
system in its basic
form and does not require any expansion hardware.
The
2+8
CCU is a
Y=O
system (the CCU is virtually transparent to the
serving exchange). Internal switching of the extensions and exchange
lines is done by miniature sealed relays, so the
2+8
signalling from the
CCU is totally dependent on the signalling from the extension Telephone
or System phones.
i.i.1
Central Control Unit
The
2+8
Central Control Unit is completely self-contained in a single box
unit housing the mains power unit, a single PCB on which is mounted
the main processor, facility software in PROM, two Peripheral
processors, and all switching relays and IDC connectors for the
extensions and exchange lines. No separate Network Terminating and
Test Point is required by the system. Break jacks are provided on the
exchange line IDCs.
i.i.2
Systemphone
The
2+8
System phone is exclusive to the
2+8
system, having full LSr
operation, direct selection and display status of exchange lines and
extensions and a
10
number store.
The System phones require a
10
second power up period, measured from
the moment they are plugged into the extension socket, before they can
be used.
Ll.3
Telephones
Approved Telephone extensions must be fitted with an earth recall
facility which is used for line access and hold. Telephones using Time
Break recall only are not suitable.
1.1.4
Modes of working
The
2+8
is a Hybrid small switching system. This means it can be used as
a PBX where incoming calls are routed to a controlling operator
extension or as a Keysystem where incoming calls can be answered by
any extension which is programmed to ring. In Keysystem mode the
2+8
can be set to a third option known as Exclusive line working where the
second exchange line can be dedicated to one extension user or to a
Facsimile machine. The
2+8
can also employ a mix of System phones and
approved telephones.
TPU
1371Issue3(4/91)
Introduction
1-1
Summary of Contents for 2+8
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Page 36: ...Notes 10 2 Notes 10 3 TPU 1371Issue3 4 91...
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