4.4
Commands
4 – 17
Quering
AOFF
will respond with one of the same 5 tokens as de-
scribed above, for
AGAN
.
AOFF 1
Example:
Measure reference frequency
AREF(?)
{
z
}
Set (query) the “measure the reference oscillator frequency” function
{
to
z
=
(
OFF 0
,
ON 1
)
}
. Setting
AREF
with no parameter will initiate a
reference frequency measurement cycle, and is equivalent to
AREF
1
.
The set version of
AREF
can initiate an auto measurement cycle by
commanding
AREF
to
ON
(
1
). If a currently-executing auto o
ff
set
must be cancelled in-progress, send the command
AREF
OFF
.
Quering
AREF
will respond with one of the same 5 tokens as de-
scribed above, for
AGAN
.
External lock-assist
ASST(?)
{
z
}
Set (query) the reference oscillator lock-assist function
{
to
z
=
(
OFF 0
,
ON 1
)
}
. Setting
ASST
with no parameter will initiate an auto lock-
assist cycle, and is equivalent to
ASST
1
.
The set version of
ASST
can initiate a lock-assist cycle by command-
ing
ASST
to
ON
(
1
). If a currently-executing auto lock-assist must be
cancelled in-progress, send the command
ASST
OFF
.
Quering
ASST
will respond with one of the same 5 tokens as de-
scribed above, for
AGAN
.
4.4.11
Data transfer commands
Output
OUTR?
Query the output value, in volts. The range of
OUTR?
responses is
always in the range
−
10
≤
OUTR?
≤
+
10.
Output RTI
ORTI?
Query the output value, in volts, referenced to input.
The relationship betwen
OUTP?
and
ORTI?
is
ORTI?
=
(
OUTP?
/
10 V)
×
V
FS
where
V
FS
is the full-scale voltage sensitivity, in volts. For example,
if
SENS
=
8
(
S50UV
),
V
FS
=
50
×
10
−
6
V. Then if
OUTP?
=+
3.14, then
ORTI?
returns
+
0.000015700 (15.7
µ
V input).
SR124
Analog Lock-In Amplifier
