Pots Connection Tips & Precautions - Tieline ViA User Manual

338 ViA User Manual v2.0
POTS Connection Tips & Precautions
32.7
POTS Operation Precautions
POTS performance is greatly affected by the quality of the line being used. Precautions must be
taken to ensure the Tieline codec is not sharing the line with other devices. Please remove these
possible sources of interference:
·
DSL or ADSL Modems
·
Other telephone handsets
·
Portable phone base stations
·
Unused parallel phone sockets
·
Fax machines
·
Computer modems
·
Burglar alarm systems
·
Extension bells
·
Call waiting
Call Waiting
Call waiting tones may cause the codec to malfunction. Most phone companies supply call
waiting as a feature and you will need to turn it off. Your Telco should be able to provide a
number you can dial to disabling the call waiting feature on the line.
Private Branch Exchanges
Avoid connecting the codec to a digital PBX or PABX system, key station, business system or
any other local switchboard. It may sometimes be tricky to detect if you are connected to one of
these systems, however, as a general guide, these devices require you to dial an additional digit
to access the POTS network.
WARNING: Many of these systems are digital and have non standard telephone line
operating voltages. If you attach your POTS module to a digital PABX or PBX system
permanent damage may result from the high voltage pulses these systems generate. Even if
the PBX is not digital, the performance of the codec is unlikely to be as good as a normal
POTS line.
If you have no option other than to use a PBX or PABX System, search for a fax machine. The
overwhelming majority of fax machines are designed for analog POTS line operation and are
normally on an extension optimized for fax machines and data transmission. Substitute a
normal phone for the fax machine to verify correct operation. Use a normal phone, not a venue-
supplied phone, because this may have characteristics to match the existing PBX/PABX and
not a POTS line. After confirming correct phone operation, you can unplug the phone and
attach the phone line to the codec.
Check the Length of the Line
It is desirable to have a local loop which is as short as possible, i.e. the line from your location
to the local Central Office or Local Exchange. Optimum performance can be expected for lines
up to about 2 miles (3 kilometers) in length. Line quality will be reduced over longer distances
and the codec can be expected to perform at lower bit rates. Line quality will also be affected by
the age, condition and type of cabling used, e.g. plastic insulation or paper insulation, water or
moisture entering the cable, age and state of repair of joins.
© Tieline Pty. Ltd. 2017