Stanford Research Systems DS335, User Manual

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3-4 Programming Commands
DS335 Synthesized Function Generator
KEYS(?)i The KEYS command simulates the pressing of a front panel key. The
KEYS? query returns the keycode of the most recently pressed key.
Keycodes are assigned as follows:
Key Name Key Code
FREQ 1
AMPL 2
OFFSET 3
START FREQ 4
STOP FREQ 5
SWEEP RATE 6
0 7
1 8
2 9
3 10
Vrms/HZ/DOWN 11
SEL FNC 12
Decimal Point 13
4 14
5 15
6 16
Vpp/kHz/UP 17
+/- 19
7 20
8 21
9 22
MHz/SHIFT 23
OFFS (?) x The OFFS command sets the output's DC offset to x volts. The OFFS?
query returns the current value of the DC offset. The DC offset voltage plus
the peak AC voltage must be less than 5 Volts (into 50
Ω
).
SYNC(?)I Turns the SYNC output on (i=1) or off (i=0).
TERM(?) i Sets the output source impedance to 50
Ω
(i=0), or hi-Z (i=1). The TERM?
query returns the current source impedance setting. Note that all amplitude
and offset display settings get doubled when switching from 50 Ohm to High
Impedance. Similarly, when switching from high impedance to 50 Ohm all
amplitude and offset display values get halved. The actual BNC output is not
affected by this change.
Sweep & FSK Control Commands
note: All sweep & FSK parameters may be set at any time. For the changes to have an effect be sure that
the sweep or FSK type is set correctly and that sweep or FSK is enabled (see the STYP and SWEN
commands).
FSEN(?) i Enables FSK on (i=1) or off (i=0). This function is valid only if FSK has been
selected with the SDIR command (SDIR2) or from the front panel. If the FSK
rate has been set between 0.01Hz and 50 kHz then the FSK starts following
the "FSEN1" command. If the rate has been set to 0Hz and FSK selected,
the command "FSEN1" would enable the FSK BNC input on the rear panel.
This TTL signal is sampled at a 10MHz rate and toggles between the Start
frequency and the Stop frequency.