Comtech EF Data SNM-1001L - Manual (Page 223)

13–1
Chapter 13. BUC FSK
COMMUNICATIONS
13.1 Introduction
The modulator includes capability to communicate with an ODU Block Up Converter
(BUC) using an FSK signal multiplexed onto the IF output connector along with the TX
IF signal, 10 MHX reference, and DC power to the BUC. The M&C implements
commands to control BUC functions and to query the BUC for configuration or status
information.
FSK Transmitter
Frequency
650 kHz ± 5 %
FSK Deviation ± 60 kHz nominal (+60 kHz mark)
Deviation Tolerance ± 50 kHz minimum, ± 70 kHz maximum
Output Level -5 to –15 dBm
Start Tone Time 10 ms minimum
Output Impedance 50 Ω
Start Time 710 kHz
FSK Receiver
Locking Range
Input Sensitivity
± 32.5 kHz
-15 dBm (50
Ω)
Transmission Protocol
Baud Rate
Data Bits
Parity
Stop Bits
Message Rate
BUC Response Time
Maximum Response Time
9600 bps
8
None
1
1 every 40 msec
12 msec, typical
40 msec
Note: If the BUC does not respond within the maximum response time the IDU should
cyclically repeat the command.