Stanford Research Systems DS335, User Manual

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Programming Commands 3-5
DS335 Synthesized Function Generator
*TRG The *TRG command triggers a single sweep. The trigger source must be set
to SINGLE (see the TSRC command below).
SDIR(?)i Sets the sweep direction. 0 = Ramp (unidirectional), 1 = Triangle
(bidirectional), 2 = enable FSK (disable sweeps).
STYP (?) i The STYP command sets the sweep type to i. The correspondence of i to
type is shown in the table below. The STYP? query returns the current
sweep type. Refer to the SDIR command for sweep direction.
i Waveform
0
LIN SWEEP
1 LOG SWEEP
SPFR (?) x The SPFR command sets the sweep stop frequency to x Hertz. An error will
be generated if the sweep frequency is less than or equal to zero or greater
than allowed by the current function. The SPFR? query returns the current
sweep stop frequency. If the stop frequency is less than the start frequency
(the STFR command) a downward sweep from maximum to minimum
frequency will be generated. The stop frequency is also used in the FSK
mode.
SRAT (?) x
The SRAT command sets the trigger rate for internally triggered single
sweeps and FSK to x Hertz. x is rounded to two significant digits and may
range from 0.01 Hz to 1 kHz for sweeps and 0.01Hz to 50kHz for FSK. The
SRAT? query returns the current trigger rate. If the rate is set to 0Hz and
FSK is enabled (SDIR = 2) then the external FSK BNC is used to toggle
between the start and stop frequencies.
STFR (?) x The STFR command sets the sweep start frequency to x Hertz. An error will
be generated if the sweep frequency is less than or equal to zero or greater
than allowed by the current function. The STFR? query returns the current
sweep start frequency. If the start frequency is greater than the stop
frequency (the SPFR command) a downward sweep from maximum to
minimum frequency will be generated. The stop frequency is also used in the
FSK mode.
SWEN(?) i Enables sweeps on (i=1) or off (i=0). If the continuous sweep is selected,
enabling sweeps will start the sweep with the specified rate. If triggered
single sweep is selected and sweeps are enabled then the DS335 waits for a
front panel trigger or a *TRG command to start the sweep.
TSRC (?) i The TSRC command sets the trigger source for sweeps to i. The
correspondence of i to source is shown in the table below. The TSRC?
query returns the current trigger source.
i Waveform
0 SINGLE
1 INTERNAL RATE
For single sweeps the *TRG command triggers the sweep.