Antenna Aiming; Antenna Swr Check; Data Buffer Setting; Hoptime Setting - Microwave Data Systems MDS TransNET 900 Installation & Operation Manual

Antenna Aiming

For optimum performance of directional antennas, they must be accurately
aimed in the direction of desired transmission. The easiest way to do this is to
point the antenna in the approximate direction, then use the remote radio's
command (Received Signal Strength Indicator) to further refine the
RSSI
heading for maximum received signal strength.
In an MAS system, RSSI readings are only meaningful when initiated from a
remote station. This is because the master station typically receives signals
from several remote sites, and the RSSI would be continually changing as the
master receives from each remote in turn.

Antenna SWR Check

It is necessary to briefly key the transmitter for this check by placing the radio
in the mode
SETUP
radio, enter
DKEY
operation, enter
Q
The SWR of the antenna system should be checked before the radio is put into
regular service. For accurate readings, a wattmeter suited for 1000 MHz is
required. One unit meeting this criteria is the Bird Model 43 directional
wattmeter with a 5J element installed.
The reflected power should be less than 10% of the forward power (≈2:1
SWR). Higher readings usually indicate problems with the antenna, feedline
or coaxial connectors.

Data Buffer Setting

The default setting for the data buffer is
with the lowest possible latency and improves channel efficiency. MODBUS
and its derivatives are the only protocols that should require the buffer to be
turned on. See "BUFF [ON, OFF]" on page 28

Hoptime Setting

The default hop-time setting is
increase throughput, but at the cost of increased latency. A detailed
explanation of the

Operation at 115200 bps

Burst throughput at 115200 bps is supported at all settings. The radio will
always buffer at least 500 characters. Sustained throughput at 115200bps is
only possible when the data path is nearly error free and the operating settings
have been properly selected. For sustained operation at 115200 bps, use the
following settings:
20 MDS TransNET 900 I&O Guide
(Page 35) and using the
; to disable the
SETUP
or .)
QUIT
(7 ms). An alternate setting of
7
command can be found on
HOPTIME
,
SAF OFF FEC OFF
command. (To unkey the
KEY
mode and return the radio to normal
. This allows the radio to operate
OFF
for details.
, ,
REPEAT 0 RETRY 0
MDS 05-2708A01, Rev. B
is used to
28
Page 31.
,
HOPTIME 28
.