Independent Tx And Rx Function; Verification; Firmware Updates - Comtech EF Data SLM-5650A Installation And Operation Manual

1.3.1.4

Independent Tx and Rx Function

The Tx (modulator) and Rx (demodulator) sides of the modem are functionally independent and
separately controllable. The baseband Tx and Rx sides of a communications channel passing
through the modem are independently configurable, including the ability to select different
parameters (to include data rate, modulation, and coding) in support of asymmetrical operation.
Data interfaces and IF interfaces are not independent.
Example: If the TIA/EIA-530 interface is selected, DO NOT USE TIA/EIA-530
to transmit and a HSSI interface to receive. The same principle applies to the
IF interfaces: If 70/140 is selected, DO NOT USE 70/140 to transmit and the L-
Band interface to receive.
1.3.1.5

Verification

The SLM-5650A includes test modes and loopbacks for rapid verification of the correct
functioning of the modem. Of particular note is the IF loopback, which permits the user to perform
a quick diagnostic test without having to disturb external cabling. During the loopback, the receive
frequency is temporarily changed to match the Tx side, and an internal RF switch connects a
sample of the modulator to the demodulator input. When normal operation is again selected, the
previous value is restored.
1.3.1.6

Firmware Updates

Chapter 5. FIRMWARE UPDATE
The SLM-5650A stores its firmware in flash memory, which allows the modem to upload firmware
downloads from an external PC once you establish Ethernet connectivity. Firmware updates for
the base modem, GbE Interface Module, and NP Interface Module may be obtained free from
Comtech EF Data via the CEFD Web site, or via e-mail from Comtech EF Data Product Support
during normal business hours. (Note that TRANSEC Module firmware updates must be requested
directly from Comtech EF Data Product Support.)
Introduction 1–7
SLM-5650A Satellite Modem
Revision 10
MN-SLM-5650A