Oki 5700 - Manual (Page 130)

English
E-2 Appendix E
In order to prevent the misdirection of calls and network interference,
please ensure that all manually programmed telephone numbers are
correctly entered.
This apparatus is also approved for use as an extension instrument to
compatible PBXs. The supplier of the apparatus should be consulted for an
up-to-date list of PBXs with which this apparatus is compatible.
The handset can be used to make “999” calls to the Emergency Services.
The second telephone or answering machine must be connected to the
TEL 2 jack by means of the two-way adapter provided.
The apparatus is suitable for connection to PBXs which return Secondary
Proceed Indication. In these situations, please insert pauses between the
initial access digit and the number to be dialled to the PSTN.
Series Connection
NOTE 1
The machine causes a voltage drop of 1.35V when passing a PSTN current
up to and including 40mA dc. Do not connect the machine with apparatus
which, with associated wiring causes the aggregate of the voltage drops to
exceed a value of 2V at a PSTN line current of 40mA dc.
The 2V level indicates the maximum impairment that may be introduced
between the terminal apparatus and the Network Terminal Point (NTP) of
a Relevant Branch system (RBS) containing the apparatus.
Only one facsimile transceiver should be connected between any series
connected apparatus and the PSTN.
Difficulties may occasionally be experienced when making calls from
other apparatus connected to the PSTN via the series apparatus. Such
difficulties may include:
i) Difficulty in making calls
ii Problems in telephone conversion being experienced by both parties
to the call
iii) Such that any apparatus which forms part of the RBS or is connected
via it, is so connected that no signals of any kind may be conveyed
between that apparatus and a PSTN circuit or vice-versa, except by
means of other apparatus that does not materially affect the electrical
conditions presented to one another by that apparatus and the PSTN.
Further information is contained in the proposed British Standard for RBS
to PSTN lines.