Using Extension Telephones - Brother T74 Owner's Manual

Multi-Line Connections (PABXs)
Most offices use a central telephone system. While it is often relatively simple to connect the
machine to a key system or a PABX (Private Automatic Branch Exchange), we suggest that you
contact the company that installed your telephone system and ask them to connect the machine for
you. It is advisable to have a separate line for the machine. You can then leave the machine in FAX
ONLY Mode to receive faxes any time of day or night.
If the machine is to be connected to a multi-line system, ask your installer to connect the unit to the
last line on the system. This prevents the unit from being activated each time a telephone call is
received.
If you are installing the machine to work with a PABX:
1
It is not guaranteed that the unit will operate correctly under all circumstances with a PABX.
Any cases of difficulty should be reported first to the company that handles your PABX.
2
If all incoming calls will be answered by a switchboard operator, it is recommended that the
Answer Mode be set to MANUAL. All incoming calls should initially be regarded as telephone
calls.
3
The unit may be used with either pulse or tone dialling telephone service.

Using Extension Telephones

It may be that your premises are already wired with parallel extension telephones, or you intend to
add extension telephones to your line, in addition to your machine. While the simplest arrangement
is straightforward parallel connection, there are some reasons as to why this arrangement will cause
unsatisfactory service, the most obvious of which is inadvertent interruption of a facsimile
transmission by someone picking up an extension telephone in order to make an outgoing call.
Additionally, remote activation may not operate reliably in such a simple configuration.
This machine may also be set to make a delayed transmission (i.e. a transmission at a pre-set time).
This pre-set job may coincide with someone picking up an extension handset.
Such problems can easily be eliminated however, if you arrange modification of your extension
wiring circuit, such that extension devices are connected "downstream" of your machine, in a
master/slave configuration. In such a configuration, this machine can always detect whether a
telephone is in use, thus it will not attempt to seize the line during that time. This is known as
"telephone off-hook detection."
The inadvisable configuration is shown in figure 1 below, and the recommended master/slave
configuration is shown in figure 2.
This new connection configuration can be arranged by your contacting BT, Kingston upon Hull
Telecommunications, your PABX maintainer or a qualified telephone installation company as
appropriate. Simply explained, the extension telephone circuit should be terminated on a normal
modular plug (BT 431A style), which in turn should be inserted into the modular socket of the white
"T"-shaped connector provided as part of the line cord assembly.
Preparation and Simple Use Guide
9