Stanford Research Systems DS345, Manual

Page: 53 / 139

Programming Commands
3-3
DETAILED COMMAND LIST
The four letter mnemonic in each command sequence specifies the com-
mand. The rest of the sequence consists of parameters. Multiple parame-
ters are separated by commas. Parameters shown in {} are optional or may
be queried while those not in {} are required. Commands that may be quer-
ied have a question mark ? in parentheses (?) after the mnemonic. Com-
mands that may ONLY be queried have a ? after the mnemonic. Commands
that MAY NOT be queried have no ?. Do not send ( ) or { } as part of the
command.
All variables may be expressed in integer, floating point or exponential for-
mats ( ie., the number five can be either 5, 5.0, or .5E1). The variables i and
j usually take integer values, while the variable x takes real number values.
Function Output Control Commands
AECL
The AECL command sets the output to the ECL levels of 1 V peak-to-peak
with a -1.3 V offset. That is, from -1.8V to -0.8V.
AMPL (?) x
The AMPL command sets the output amplitude to x. The value x must con-
sist of the numerical value and a units indicator. The units may be VP (Vpp),
VR (Vrms), or DB (dBm). For example, the command AMPL 1.00DB will set
the output to 1.0 dBm. For arbitrary waveforms the amplitude may
only
be
set in terms of peak-to-peak value. Note that the peak AC voltage (Vpp/2)
plus the DC offset voltage must be less than 5 Volts. Setting the amplitude
to 0 Volts will produce a DC only (no AC function) output controlled by the
OFFS command.
The AMPL? query will return the amplitude in the currently displayed units.
For example, if the display is 3.0 Vrms the AMPL? query will return 3.0VR. If
a units indicator is sent with the AMPL? query (such as, AMPL? VP) the dis-
played units will be changed to match the units indicator and the amplitude
returned in those units.
ATTL
The ATTL command sets the TTL output levels of 5 V peak-to-peak with a
2.5 V offset. That is, from 0V to 5V.
FREQ (?) x
The FREQ command sets the output frequency to x Hertz. The FREQ?
query returns the current output frequency. The frequency is set and re-
turned with 1
µ
Hz resolution. If the current waveform is NOISE an error will
be generated and the frequency will not be changed. This command does
not
set the sampling frequency for arbitrary waveforms- see the FSMP com-
mand.
FSMP (?) x
The FSMP command sets the arbitrary waveform sampling frequency to x.
This frequency determines the rate at which each arbitrary waveform point is
output. That is, each point in the waveform is played for a time equal to 1/
FSMP. The allowed values are 40 MHz/N where N is an integer between 1
and 2
34
-1. If x is not an exact divisor of 40 MHz the value will be rounded to
the nearest exact frequency.. The FSMP? query returns the current arbitrary
waveform sampling frequency.
FUNC (?) i
The FUNC command sets the output function type to i. The correspondence
of i and function type is shown in the table below. If the currently selected
frequency is incompatible with the selected function an error will be generat-