05-4481A01, Rev. A
GE MDS TransNET Quick Start Guide
5
Successful troubleshooting of an MDS transceiver system is not
difficult, but requires a logical approach. It is best to begin
troubleshooting at the Master station, as the rest of the system
depends on the Master for polling instructions and synchronization
data. If the Master station has problems, the operation of the entire
network will be affected.
When communication problems are found, it is good practice to
begin by checking the basics. All radios in the network must meet
these basic requirements:
•
Adequate and stable primary power
•
An efficient and properly aligned antenna system
•
Secure connections (RF, data & power)
•
Proper programming of the radio’s operating parameters,
especially Operating Mode (MODE), Network Address
(ADDR), and interface Baud Rate (BAUD). For TransNET
2400 check the sub-band (BAND).
•
The correct interface between the radio and the connected
data equipment (proper cable wiring, data format and timing).
•
In store-and-forward systems there are several areas that
should be checked or evaluated:
•
Look for duplicate XADDR values on MODE M and MODE X
radios. Duplicates will cause failures unless the radios are too
far apart to hear each other.
•
Check for errors in the synchronization qualifiers, XPRI and
XMAP, on corresponding Remote radios.
•
Verify SAF is enabled at the Master radio.
4.1
LEDs
Table 6
describes how to use the LEDs as a troubleshooting aid
whenever you suspect a problem with the transceiver.
4.2
Alarm Codes
When an alarm condition exists, the transceiver creates an alarm
code. These codes can be very helpful in resolving many system
difficulties.
4.2.1
Checking for Alarms—STAT command
To check for the presence of alarms, enter STAT. If no alarms
exist, the message NO ALARMS PRESENT appears at the top of
the display.
If an alarm does exist, a two-digit alarm code (00–31) is displayed,
and it is identified as a major or minor alarm. A brief description of
the alarm is also given. Alarm codes and their meanings are listed
in
Table 7
.
If more than one alarm exists, the word MORE appears at the
bottom of the screen; additional alarms can be viewed by pressing
ENTER.
4.2.2
Major Alarms versus Minor Alarms
Major alarms report serious conditions that generally indicate a
hardware failure, or other abnormal condition that will prevent (or
seriously hamper) further operation of the transceiver.
With the exception of alarm code 00 (network address not
programmed), major alarms generally indicate the need for factory
repair. Contact MDS for further assistance.
Minor alarms report conditions which, under most circumstances,
will not prevent transceiver operation. This includes
out-of-tolerance conditions, baud rate mismatches, etc. The cause
of these alarms should be investigated and corrected to prevent
system failure.
4.0
TROUBLESHOOTING
Table 6: LED Indicator Descriptions
Name
Description
PWR
• Continuous—Power is applied to the radio; no prob-
lems detected
• Flashing (5 times-per-second)—Fault indication. See
Section 4.0,
Troubleshooting
.
• Off—Radio is unpowered or in Sleep mode
SYNC
Continuous—Radio is receiving/sending synchronization
frames
On within 10 seconds of power-up under normal condi-
tions
TXD
Transmit data activity on the DB-9 DATA interface con-
nector
RXD
Receive data activity on the DB-9 DATA interface con-
nector
Table 7: Alarm Codes
Alarm
Code
Alarm
Type
Description
00
Major
The network address is not programmed.
01
Major
Improper firmware detected for this radio model.
04
Major
One or more of the programmable synthesizer
loops is reporting an out-of-lock condition.
08
Major
The system is reporting that it has not been calibrat-
ed. Factory calibration is required for proper radio
operation.
10
Major
The DSP was unable to properly program the sys-
tem to the appropriate defaults. A hardware prob-
lem may exist.
12
Major
Receiver time-out alarm.
16
Minor
The unit address is not programmed.
17
Minor
A data parity fault has been detected on the DATA
connector. This usually indicates a parity setting
mismatch between the radio and the RTU.
18
Minor
A data framing error has been detected on the
DATA connector. This may indicate a baud rate mis-
match between the radio and the RTU.
29
Minor
RF output power fault detected. (Power differs by
more than 2 dB from set level.) Often caused by
high antenna system SWR. Check antenna, feed-
line and connectors.
30
Minor
The system is reporting an RSSI reading below
–105 dBm.
31
Minor
The transceiver’s internal temperature is approach-
ing an out-of-tolerance condition. If the temperature
drifts outside of the recommended operating range
and the transceiver may fail.
