Troubleshooting Chart; No Synchronization With Master - Microwave Data Systems MDS TransNET 900 Installation & Operation Manual

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7.3 Troubleshooting Chart

Table 14

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.

Difficulty

Unit is

inoperative.

Interference is

suspected.

No synchroniza-

tion with master,

or poor overall

performance.

BER is too high.

Data throughput

is spotty.

Latency is too

high.

MDS TransNET 900 I&O Guide

Table 14. Troubleshooting chart

Recommended System Checks

a.Check for the proper supply voltage at the power connector.

b.The transceiver's internal fuse may have opened. Refer to

tion 7.5

below for replacement instructions.

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

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.

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

34). 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

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.

a.Reduce the REPEAT count.

b.Turn BUFF OFF. BUFF ON insures that no gaps occur in the

data, but this comes at the cost of increased latency.

c. Make sure HOPTIME is set to 7.

(Page

36).

MDS 05-2708A01, Rev. B

Sec-

(Page

37)

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