TECHNICAL NOTE – OPERATION OF MT4000 TWTA
10/24/03
TN4000-3
MCL, INC.
24 of 46
4.2
HPA Operating Modes
The following paragraphs describe the operating states of the HPA. The reported status for these
states is shown in the table below.
STATUS
STATE
FIL
OFF
DELAY
STBY
XMT
SELD
XMT
SUM
FAULT
DC POWER ON, NO FILAMENT
ON
OFF
OFF
OFF
OFF
OFF
DC POWER ON, NO FILAMENT, WITH
A FAULT
ON
OFF
OFF
OFF
OFF
ON
DURING FILAMENT DELAY,
WITHOUT TRANSMIT SELECTED
OFF
ON
OFF
OFF
OFF
OFF
DURING FILAMENT DELAY, WITH
TRANSMIT SELECTED
OFF
ON
OFF
ON
OFF
OFF
DURING FILAMENT DELAY, WITH A
FAULT
OFF
ON
OFF
OFF
OFF
ON
STANDBY
OFF
OFF
ON
OFF
OFF
OFF
AFTER FILAMENT DELAY, WITH A
FAULT
OFF
OFF
OFF
OFF
OFF
ON
TRANSMIT
OFF
OFF
OFF
OFF
ON
OFF
DURING FAULT COUNTER CYCLE,
WITH TRANSMIT IMMINENT
OFF
OFF
OFF
ON
OFF
OFF
Notes:
1.Sum Fault state disables Standby, Transmit, or Transmit Selected.
2.Alarms can occur in any of the above states.
3.Standby and Transmit are mutually exclusive.
4.Transmit state disables Filament Off.
4.2.1 Filament
Off
This state occurs after a Filament Off command (Local, Remote, or Computer) has been issued.
In this state the TWTA logic will be activated along with any power supplies or cooling required
to keep the logic powered on. During this state the HVPS & Filament PS circuits will be shut
down. The HPA cannot be in Transmit when this state is initialized.
