Appendix B. Remote Control; Introduction - Comtech EF Data LPOD Hardware Installation And Operation Manual

Appendix B. REMOTE CONTROL

B.1

Introduction

This section describes the operating features of the LPOD C-/Ku-Band Outdoor Amplifier/Block
Up Converter (BUC) via remote control. A few key parameters and procedures are summarized,
followed by detailed instructions of remote control communication commands and queries.
B.1.1 RF Input Level
The required RF input level to reach the full rated output power of the SSPA is determined by the
individual amplifier maximum gain and power rating. For example, if the test data of an SSPA rated
for 250W (54 dBm) indicated a gain of 75 dB, then a signal of 54 dBm – 75 dB = -21 dBm would
approximately give the rated output power. Increasing input power beyond this level would result in
an output signal with increasingly higher levels of distortion. Of course, if the LPOD attenuation
control is utilized, a higher level input signal level can be accommodated. The maximum input level
should never exceed 15dBm, or permanent damage to the unit may occur.
B.1.2 Attenuator Control
The LPOD gain can be attenuated over its specified range by exercising the
details for the format of this command are found later in this chapter.
B.1.3 Mute Control
The LPOD may be muted via software or discrete control. Exercising the
"software" mute the unit. The LPOD also may be "hardware" muted by pulling Pin 'S' on the J6
(COM1) Discrete control connector to ground (See Chapter 2. SYSTEM CONNECTIONS,
INSTALLATION
The Mute command provides over 60 dB of RF on/off isolation. However, the Mute command
only turns off the first few low power stages of the amplifier, the high power stages remain on.
By allowing the higher power transistors to stay on, the LPOD remains in more thermally stable
state should the mute condition be removed.
If the user desires to completely turn off the bias to the entire amplifier (perhaps to conserve
energy in a redundant system), both the
normal transmit operation,
OPERATION).
AND
MUT=1
and
MUT=0 AMP=1
and commands should be executed. For
AMP=0
are required.
command. The
ATT
command will
MUT=1