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LPOD C-, X-, or Ku-Band Outdoor Amplifier / Block Up Converter (BUC)
Serial Interface Operation
5.2.2 Attenuator Control
You may use the ATT command to attenuate the LPOD gain over its specified range. Full details are available in Section 5.4.
5.2.3 Mute Control
You may mute the LPOD via software or discrete control:
• Software – Using the MUT=1 command will "software" mute the unit.
• Discrete Control – When using 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 while 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 you wish to completely turn off the bias to the entire amplifier (perhaps to conserve energy in a redundancy 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.
• I2C internal bus communications fault.
• Thermal Shutdown – A temperature fault is indicated if the unit is +>90°C. This creates a summary fault and will cause the
unit to mute itself and switch to the back-up unit (if in a redundancy system). However, the 10V supply to the FET transistors
will remain on until the unit reaches the thermal shutdown temperature of ≥ >95°C. For protection reasons, the unit will shut
down the 10V supply to the power transistors at temperatures >95°C.
• Firmware checksum error at power up.
• FPGA done indicator error at power up.
• *Block Up Converter (BUC) unlocked.
5–2
MN-LPOD
Revision 14
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