SIGMA BENEFON TDP-52-SN3 - Manual (Page 165)

27.1.1999
Xo0245e4_fm5.fm 4
Product: LIF-40 (Line Interface) / YO0245
9.1.3.1 TROUBLE SHOOTING
When moving about or in an area with poor reception, radio fade and changes
between base stations will interrupt radio contact. Typical symptoms of data transfer
errors are random characters, missing characters, loss of contact, drop in data trans-
fer speed, missing lines and error lines in telefaxes.
The data transfer device and program should withstand momentary breaks.
An error correcting modem is only of value if it is available at both ends of the trans-
mission.
It is recommended to stay in one place during data transfer, and to select a location
with as strong field strength as possible.
The line interface takes its power from the hand-phone battery, so allow for the
increased consumption by first charging the battery or by connecting the charger
using the branching unit.
Use the cellular phone exchange data transfer service to eliminate problems caused
by channel changing.
Modem settings:
- long elapsed time range for carrier wave control (ATS10=30)
- short data blocks (AT&BS0)
- error correction ON (AT&E2)
- speed select (AT$MB2400)
There are tele-devices that take their power from the telephone line, in which case
the line interface supply of 25 mA will not be enough. These, generally non-
approved devices are not recommended for use with the line interface.
Typically, problems arise from modem or telefax internal settings (see tele-device
operating manual). Data transfer may function normally with a fixed telephone line,
but not with the handportable. Frequently the settings for radio transmission have to
be found by experimentation.
9.1.3.2 Functional Description
You can use the line converter for connecting your Benefon handportable to any
two-wire data terminal approved for use in the public telephone network. The line
converter receives its operation power from the handportable battery; a separate
branching unit enables a charging device to be simultaneously connected to the
handportable. The line converter consists of the following operations: ring voltage
and line current generation, audio input and output, line current detection (HOOK),
and low-power standby mode.
The line converter can be divided into seven different functional units: audio, fre-
quency divider, chopper, current sink, I2C connection, free/reserved tone genera-
tion, line switches for ring signal, and HOOK detection.