4.4
Commands
4 – 11
Reference DC bias enable
BION(?)
{
z
}
Set (query) the reference output DC bias
{
to
z
=
(
OFF 0
,
ON 1
)
}
.
Turning the bias on enables DC biasing of the reference output signal.
BION 1
Example:
Reference DC bias magnitude
BIAS(?)
{
g
}
Set (query) the bias magnitude
{
to
g
}
, in volts. The default value is
BIAS
0.00
.
Allowed values for
BIAS
may be restricted based on the value of
SLVL
. See section 3.4 for details.
BIAS?
Example:
0.001250000
Reference output waveform
FORM(?)
{
z
}
Set (query) the reference output waveform
{
to
z
=
(
SQUARE 0
,
SINE
1
)
}
.
FORM SINE
Example:
4.4.5
Input commands
Input source
ISRC(?)
{
z
}
Set (query) the input source configuration
{
to
z
=
(
A 0
,
AMINUSB 1
,
CUR1E6 2
,
CUR1E8 3
)
}
.
The first two settings (
ISRC
A
and
ISRC
AMINUSB
) select the voltage
input preamp, configured for single-ended
A
input, or di
ff
erential
AMINUSB
input.
The last two settings (
ISRC
CUR1E6
and
ISRC
CUR1E8
) select the
current (transimpedance) amplifier. The current amplifier has a se-
lectable gain of either 1 M
Ω
(10
6
V
/
A) or 100 M
Ω
(10
8
V
/
A). In either
current configuration, the transimpedance gain is
in addition to
the
overall voltage gain set by the
SENS
command.
For example, if
ISRC
CUR1E8
and
SENS
S50MV
, then the overall sen-
sitivity corresponding to a full-scale (10 V) output is
50 mV
×
1
10
8
V
/
A
=
500 pA
.
ISRC?
Example:
0
SR124
Analog Lock-In Amplifier
