Comtech EF Data LPOD - Manual (Page 102)

LPOD C-, X-, or Ku-Band Outdoor Amplifier / Block Up Converter (BUC) MN-LPOD
Serial-based Remote Product Management Revision 10
5–2
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.
5.2.2 Attenuator Control
The LPOD gain can be attenuated over its specified range by exercising the ATT command. The details for the format of this command
are found later in this chapter.
5.2.3 Mute Control
The LPOD may be muted via software or discrete control:
• Software – Exercising the MUT=1 command will “software” mute the unit.
• Discrete Control – When exercising the AUX=1 command, the LPOD will be muted until Pin ‘S’ (on the ‘J6 | COM1’ Discrete Control
Connector) is pulled to ground (Pin ‘K’). At that time, the unit unmutes.
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 SPOD 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
MUT=1 and AMP=0 commands should be executed. For normal transmit operation, MUT=0 and AMP=1 are required.
5.2.4 Faults
The M&C system monitors certain key functions of the LPOD for proper operation. Should any of these parameters exceed
predetermined limits, the M&C system will declare a fault. The conditions that trigger a fault are:
• Any power supply more than ± 10% outside its nominal value.
• Fan less than 25% of maximum speed.