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Rev 1.1 | SC5520A & SC5521A
Hardware Manual
SignalCore, Inc.
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trigger the device to perform the sweep/list function defined in the LIST_MODE_CONFIG register. The
device may also be triggered via pin 21, the hardware trigger pin (TRIGIN). Hardware triggering occurs on
a high to low transition state of this pin. Note, hardware triggering is currently not available for the
SC5520A.
Hardware Trigger Modes
The device may be triggered to start a sweep or list then uses the next trigger to stop it. In triggered
start/stop mode, alternating triggers will start and stop the sweep/list. In this mode, start triggering will
always return the frequency point to the beginning of the sweep/list. It does not continue from where it
had left off from a stop trigger. The device may also be triggered to step to the next frequency with each
start trigger. This is known as the triggered step mode. Software triggering cannot perform the step
trigger function. This can only be done through hardware triggering. When hardware step triggering has
started, performing a software trigger or changing the RF mode to single fixed tone will take the device
out of step trigger state before a cycle is completed.
Trigger Out Modes
The device can be set to send out a high to low transition signal when the configuration of a frequency by
the device is completed; that is, it has completed all necessary computations, and has successfully written
data to the appropriate components. This trigger pulse can be sent on the completion of every step
frequency or on the last frequency of a sweep cycle. This trigger signal is present on pin 20 (TRIGOUT).
Default Startup Mode
The factory power-up state for the device is detailed in the following table. The default state can be
changed to the current state of either channel programmatically, allowing the user to power up the
device in the last saved state without having to reprogram.
Table 5. Factory Default Power-Up State.
RF Out
Frequency
15 GHz
Power
0.00 dBm
RF Output
Enabled
Standby
Disabled
Auto Level
Enabled
Ref Out Select
10 MHz
Ext Ref Lock
Disabled