Comtech EF Data SLM-5650B, Installation And Operation Manual

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SLM-5650B Satellite Modem
Revision 2
Front Panel Operation 5–40 MN-SLM-5650B
5.2.5.1 Test: BERT
BERT: Tx:Off Rx:Off Pat:2047 Thrsh:Med
Reset Errins Errs:=000000 BER:NoSync
Use the

arrow keys to select Tx , Rx, Pattern , Thrsh, Reset , ErrIns, Errs, or BER , and
then press [ENT] .
Use the

arrow keys to select the desired setting. Press [ENT] to execute the test.
BERT Mode Description
Tx Select to turn the transmit test pattern generator On or Off.
Rx Select to turn On or Off the receive bit error test set.
Pattern Select from the available patterns:
•
Mark – All ones.
•
Space – All zeros.
• 1:1 – A one followed by a zero and then repeats.
•
1:2 – A one followed by two zero’s and then repeats.
•
2E15-1 – A pseudo-random data pattern of 2^15 –1, compatible with standard
BERTs.
• 2E20-1 – A pseudo-random data pattern of 2^20 –1, compatible with standard
BERTs.
•
2E23-1 – A pseudo-random data pattern of 2^23 –1, compatible with standard
BERTs.
• MIL188 – A modified pseudo-random data pattern of 2^11 –1, compatible with the
MIL-188-165 test data pattern requirement of a continuous stream of 50 zero’s every
10,000 bits. This pattern has 5 normal 2047 patterns, with the fifth patterns longest
string of zero’s (11) stretched an additional 39 bits to create a lack of transitions for 50
bits approximately every 10,000 bits.
•
2047 – A pseudo-random data pattern of 2^11 –1, compatible with standard BERTs.
Thrsh Select to set Thrsh at Hi, Med, or Low.
Reset Select to restart the BER test and clear the error and BER displays.
ErrIns Select to insert a single error into the data stream by pressing [ENT].
Errs Select to view the absolute number of errors counted.
BER Select to view the bit error rate as measured by the modem.
The BER function can work with a Fireberd supplying the transmit data
test pattern, while only turning on the Rx Bit Error Rate tester. The
transmit test pattern generator can be turned on at the far end of the link
as long as the test patterns match the Rx BERT. An external bit error test
set can be used even when the internal bit error test set is enabled. If AIS
is enabled the data will be overwritten with all ones.
5.2.5.2 Test: LampTest
Select LampTest to perform a diagnostic run on the front panel LEDs and VFD.