Specifications

Watson TDM
Operating Manual
Watson-TDM-Manual-W.doc
Version 2.0-01
5-2
Revision: 2008-02-07
Caution:
Only power sources below maximum hazardous energy levels according IEC
60950-1 chapter 1.2.8.10 may be used as local power source. The insulation
voltage of the power source must support elevated insulation voltage according
to EN 60950-1 (at least 4 KV insulation). The power adapters available from
Schmid Telecom fulfill these requirements.
Caution:
Do not connect a 48VDC supply directly to the “AC/DC adapter” connector! High
voltage transients from the DSL line may damage other equipment connected to
the battery. A DC/DC converter with 4kV transient isolation voltage should be
used in this case and the ground connector on the tabletop modem should be
connected to ground.
Caution:
The local supply voltage input is protected against reversal of polarity but not
fused. Appropriate fusing has to be done externally.
5.3 Remote Powering
Watson TDM supports the line powering concept of SHDSL. Plug-ins can supply
remote power over the DSL copper pairs. Tabletop modems and Regenerators
can be remotely powered over these copper pairs. Remote powering is available
on all pairs of a multipair system.
5.3.1 Remote power feeding on plug-ins
Plug-ins are equipped with a remote powering circuits with the following charac-
teristics:
• Per pair remote power feed
• Cross-wiring tolerant
• Power feeding voltage within limits of EN 60950 TNV-3
• Independent current limiters on a per pair basis (microcontroller - controlled)
• Tolerant against micro-interruptions
• Automatic system restart after power failure
Remote powering is controlled through the POWER command of the monitor.
The remote powering circuit is protected against overvoltage and overcurrent,
see 11.1.1.
In case of overvoltage or overcurrent the powering is disconnected within less
than 700ms.
Note:
During the power-up phase of the plug-in the disconnect delay can be up to 900
ms.
When remote powering was disconnected by overcurrent protection then it is
switched on automatically after 10 seconds.
When remote powering was disconnected by overvoltage protection then it will
disconnected until a hardware reset is done on the plug-in (removal of the plug-in
from the subrack). In this state the plug-in LEDs 1 and 3 will be red blinking and
no monitor access is possible. The overvoltage protection is only activated by se-
rious hardware faults in the feeding circuit which require analysis and repair by
the manufacturer.