T e STANDBY button illuminates and t e OPERATE button is extinguis ed. Front panel display
s ows “Standby” on t e status bar again.
Power TWTA Off:
After placing t e TWTA in STANDBY press WARM UP button to power-down t e TWTA.
If t e TWTA was operating at ig -duty t e amplifier s ould be run in STANDBY an additional lengt
of time to allow t e TWT to cool.
Reset:
If any monitored parameter falls outside t e limits set in t e processors, t e Main processor interrupts
pulses and disengages t e ig voltage supplies in a fas ion similar to STANDBY but latc es t e
system in RESET. T e RESET button is illuminated and t e front panel display status area s ows t e
word “Reset” and t e Home screen lists t e faults w ic triggered t e RESET, toget er wit values
latc ed at t e moment t e fault occured.
After t e cause of t e fault as been corrected press t e RESET button to return t e TWTA to
STANDBY.
TWT Temperature, cooling fans, cover Interlock, VSWR and Helix Current are all directly monitored
by t e Main Control and will cause t e Main Control processor to place t e TWTA in RESET if t e
amplifier is in WARMUP, STANDBY or OPERATE.
Heater Voltage and Current, Drive Voltage, Collector Voltage and Current, Body Voltage and Cat ode
Current are all directly monitored by t e RF Control. Collector Voltage and Body Voltage will not
trigger a fault until t e TWTA is in operate. Heater Current and Heater Voltage will not trigger a fault
during a specified time after t e unit was turned on.
Grid Voltage and t e RF Control Board +9V supply are andled uniquely; t ey are monitored by t e
RF Control processor but will initiate a Flas ing Reset.
Flas ing Reset:
FLASHING RESET indicates a fault w ic needs t e Main Control board to turn t e unit off to prevent
serious damage.
T e following events will trigger t e Flas ing Reset.
Grid voltage out of range or t e RF Control Board +9V supply too ig . Hig +9V supply or ig grid
voltage (absolute value) will cause a FLASHING RESET at any time w ile low grid voltage will cause
a FLASHING RESET only in WARM UP or STANDBY. Low grid voltage in OPERATE will not cause
a fault.
W en t ere is an unexpected be avior of Main Control Board or RF Control Board firmware w ic
trigger a watc dog to reset t e microcontroller. After suc a reset, t e unit will immediately go to
FLASHING RESET.
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