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CDM-625 Advanced Satellite Modem
Front Panel Operation
To edit the Min or Max delay, use the
arrow keys to change that digit. Press ENTER when done.
▲▼
5.2.1.8.4 CONFIG: CnC PMSI-Control
CnC PMSI Mode: Idle
(Idle, Redundancy, Talk, Listen)
The Pre-Mapped Symbol Interface (PMSI) is an RS-485 multi-drop bus system where one device
transmits and all other devices on the multi-drop bus are configured to receive. Its function, as
associated with DoubleTalk Carrier-in-Carrier, permits the modulator in a selected unit to
provide a direct copy of its output (the outbound interferer) to one or many other modems. The
other modem(s) may then choose to take the PMSI signal and use it for its own CnC reference.
This applies to 1:1 and 1:N systems, and to certain other configurations.
In order to use this mode of operation, you must connect the appropriate cable to the PMSI
connector on the rear panel of each modem:
•
For 1:N multi-drop applications – Use Comtech EF Data cable P/N CA-0000275;
•
For 1:1 applications – Use Comtech EF Data cable P/N CA-0000276.
Contact Comtech EF Data Customer Service for further details about either cable.
Use the
arrow keys to select the desired PMSI control configuration, and then press ENTER.
▲▼
Note the following:
Selection
Idle
Redundancy
Talk
Listen
◄ ►
Function
Select when CnC is not used.
Select when CnC is used in a 1:1 or 1:N redundancy applications.
Select w hen C nC i s us ed i n o ther c onfigurations, or f or m anual t esting ( the m odem w ill
transmit a copy of its baseband modulated signal on the PMSI port).
Select when CnC is used in other configurations, or for manual testing (the modem will receive
the P MSI s ignal, and l ock its m odulator t o t his, per mitting t he C nC m odule t o us e t he ot her
modem's reference outbound interferer).
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arrow keys to select a digit to edit, and then use the
Revision 13
MN-CDM625
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