Chapter 13. Buc Fsk Communications; Introduction - Comtech EF Data SNM-1001L Installation And Operation Manual

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
FSK Deviation
Deviation Tolerance
Output Level
Start Tone Time
Output Impedance
Start Time
FSK Receiver
Locking Range
Input Sensitivity
Transmission Protocol
Baud Rate
Data Bits
Parity
Stop Bits
Message Rate
BUC Response Time
Maximum Response Time
Note: If the BUC does not respond within the maximum response time the IDU should
cyclically repeat the command.
Chapter 13. BUC FSK
COMMUNICATIONS
650 kHz ± 5 %
± 60 kHz nominal (+60 kHz mark)
± 50 kHz minimum, ± 70 kHz maximum
-5 to –15 dBm
10 ms minimum
50 Ω
710 kHz
± 32.5 kHz
-15 dBm (50Ω)
9600 bps
8
None
1
1 every 40 msec
12 msec, typical
40 msec
13–1