65
2.048Mbps Wireless Modem
TECHNICAL: 0118 931 2233
Changing the modem rate above the default value results in the following:
•
The higher the modem rate, the lower the sensitivity. Achievable distances decrease
as the modem rate increases.
•
The higher the modem rate relative to the LIU data rate, the higher the effective
bandwidth. Better use is made of the frequency diversity capability inherent to the
frequency hopping mechanism.
In conclusion, providing that the received signal level is sufficient, selecting a higher modem
rate can significantly improve performance in the presence of interference.
Hoping Sequence
Current HOPPING SEQUENCE and HOPPING STANDARD are displayed. The number of
available hopping sequences depends on the Hopping Standard of each country. The Hopping
Standard is set in the factory. If several links in the same area are used (without using the
synchronization feature), select a different hopping sequence for each pair of 2.048Mbps
Wireless Modems. Master and Slave units must use the same hopping sequence. If co-located
units are synchronized, the same hopping sequence should be used for all units (or else the
synchronized units will interfere with each other as though not synchronized) – the
synchronization process verifies that each pair uses a sequence that is sufficiently
“shifted” in
frequency relative to sequences used by other pairs.
Add/Remove Channels from Test Sequence
Selection of this option in the RADIO and MODEM Parameters menu opens the
Add/Remove Channels from Test Sequence menu. This menu allows you to determine the
specific channels to be used when Test Sequence is used as the Hopping Standard.
Test
Sequence should only be used as the Hopping Standard by authorized Black Box
technicians.
Any changes to the Test Sequence channels shall have no effect when regular
Hopping Standards are being used. Therefore, do not attempt to select this option or to
modify the test sequence channels under normal conditions.
REMOTE Parameters
2.048Mbps Wireless Modem supports full management of the remote unit, providing that
there is a working link between the two units. Therefore the user should refrain from making
changes to the remote units that may result in a complete loss of the link. The Remote
Parameters menu gives you access to the following parameters:
•
Switch to remote monitor
•
Switch to local monitor
•
PING remote unit
•
Download remote database to remote unit
