ComStream CM601, Инструкция по установке и эксплуатации

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4-12 Installation
Acquire the Carrier
In a standard configuration, the CM601 automatically acquires the carrier in a few
seconds when the:
E
b
/N
0
level is greater than 4 dB
Symbol rate is greater than 200 ksps
The following occurs when carrier acquisition is complete:
Rx Sync message on the front panel changes from white to green
Unsolicited
ST 0
message appears on the ASCII remote terminal screen
If the modem does not acquire the carrier within a few minutes, an acquisition
failure error code will display. If this occurs, ensure that:
External connections are attached correctly to the other equipment
Configuration parameters on the modem card are compatible; change the
parameters as needed
Modulator output is enabled by issuing EM 1
Signal-to-noise ratio is sufficient for operation
Modem has searched the entire acquisition range; check the AR parameter
Signal is present on the RxIF connector
Receive carrier is at the expected frequency
AG parameter is at an acceptable level
Value of 60 to 170 indicates good signal level
Value of 255 indicates no signal
For additional help in solving common acquisition problems, refer to the chapter
on troubleshooting and maintenance.
Acquisition Commands
Use the remote terminal or the front panel to issue the commonly used acquisition
commands shown in Table 4-4.
For detailed command information, refer to the CM601 Reference Guide.
Table 4-4 Commonly Used Acquisition Commands
Command Function Remote Command Front Panel Command
Acquisition Offset Frequency AO None*
Acquisition Mode AQ Acquisition
Acquisition Range AR None*
Receiver Carrier Offset RO Rx Offset
* This entry does not appear on the front panel. Use the front panel terminal emulator (:AA) to enter this command from
the front panel.