User's Manual

48 MDS TransNET I&O Guide MDS 05-2708A01, Rev. D
7.3 Troubleshooting Chart
Table 19 provides suggestions for resolving system difficulties that may be
experienced in the radio system. If problems persist, contact the factory for
further assistance. Refer to the inside back cover of this guide for contact
information.
Table 19. Troubleshooting Guide
Difficulty Recommended System Checks
Unit is
inoperative.
a.Check for the proper supply voltage at the power connector.
b.The transceiver’s internal fuse may have opened. Refer to Sec-
tion 7.5 below for replacement instructions.
Interference is
suspected.
a.Verify that the system has a unique network address. Nearby
systems with the same address will cause interference.
b.Check for interference by locking out affected zone(s) using the
SKIP command (Page 41).
c.If omnidirectional antennas are used on Remote stations, con-
sider changing to directional antennas. This will often limit inter-
ference to and from other stations.
No synchroniza-
tion with Master,
or poor overall
performance.
a.Check for secure interface connections at the radio and the
connected device.
b.Check the antenna, feedline and connectors. Reflected power
should be less than 10% of the forward power reading
(SWR ≈ 2:1 or lower).
c.If the Remote radio is in synchronization, but performance is
poor, check the received signal strength using the RSSI com-
mand (Page 38). If RSSI is low, it may indicate antenna prob-
lems, or misalignment of directional antenna headings.
d.Verify proper programming of system parameters: mode, net-
work address, data interface baud rate, transmitter power, CTS
delay, etc. For store-and-forward applications, also verify the
following: SAF is ON; extended address is properly pro-
grammed at each extension; Remotes are using the proper val-
ues for XPRI and XMAP.
e.Check for alarms using the STAT command (Page 43)
BER is too high.
Data throughput
is spotty.
a.The RETRY and REPEAT commands may be increased to
deal with interference, or decreased to increase throughput
and reduce latency.
b.Try turning on FEC. FEC on gives some coding gain, but
comes at the cost of reduced throughput.
Latency is too
high.
a.Reduce the REPEAT count.
b.Turn BUFF OFF. BUFF ON ensures that no gaps occur in the
data, but this comes at the cost of increased latency.
c.Make sure HOPTIME is set to 7.