Figure 3-23. Rf Loopback; Figure 3-24. If Loopback - Comtech EF Data SLM-3650 Installation And Operation Manual

SLM-3650 Satellite Modem
Operation
IBS or IDR
CUSTOMER
INTERFACE
DATA
REMOTE SERIAL
INTERFACE
FAULT INDICATORS
SATELLITE MODEM
Note: When RF loopback is turned ON, the demodulator receive frequency is programmed to be the same frequency as the
modulator transmit frequency. This test mode will verify the satellite link without changing the programmed frequency of the
demodulator. When RF loopback is turned OFF, the demodulator is programmed back to the previous frequency.
CUSTOMER
IBS, IDR or 308-2
DATA
INTERFACE
REMOTE SERIAL
INTERFACE
FAULT INDICATORS
SATELLITE MODEM
Note: When IF loopback is turned ON, the demodulator is looped back to the modulator inside the modem and the demodulator is
programmed to the same frequency as the modulator. This test mode will verify the operation of the modem. When IF loopback is
turned OFF, the demodulator is programmed back to the previous frequency and is reconnected to the IF input.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
DATA
ENCODER/
MODULATOR
MICRO-
COMPUTER
DEMODULATOR/
DECODER

Figure 3-23. RF Loopback

ENCODER/
MODULATOR
MICRO-
COMPUTER
DEMODULATOR/
DECODER

Figure 3-24. IF Loopback

3–76
TRANSMIT RF
TX = 70 MHz
POWER SUPPLY AC POWER
RX = 73 MHz
RECEIVE RF
RF LBK = 70 MHz EQUIPMENT
LOOPBACK CHANGES DEMOD
RECEIVE FREQUENCY TO
70 MHz WITHOUT LOSING
ORIGINAL PROGRAMMING
INFORMATION.
TRANSMIT RF
POWER SUPPLY AC POWER
RECEIVE RF
EQUIPMENT
Revision 3
MN/SLM3650.IOM
EQUIPMENT
ANTENNA
EQUIPMENT
ANTENNA