Stanford Research Systems SR530 Manual page 27

If n is included, then v may be sent also. v is the
offset value up to plus or minus full scale in units
of volts. For example, to offset half of full scale on
the 100 µV sensitivity, v should be "50.0E-6" or an
equivalent value. However, if the sensitivity is
then changed to 200 µV, the offset is now half of
the new full scale or 100 µV. When the sensitivity
is changed, the offset is preserved as a constant
fraction of full scale rather than as a voltage
referred to the input. The expand function will, on
the other hand, preserve the value of the offset as
an input referred voltage. Once a value of v is
sent, the offsets may be turned off and on without
losing the offset values by using the O commands
without the v parameter. Note that the X and Y
offsets will affect the R output but the R offset
does not affect the X or Y output.
P {v}
If v is absent, the P command returns the
reference phase shift setting from -180 to +180
degrees. When v is included, the phase is set to
the value of v up to ±999 degrees.
Q1
Q2
QX
QY
The Q commands return the output values in
units of volts or degrees. For an input signal of 50
µV on a full scale sensitivity of 100 µV, a Q
command will return the string "50.00E-6". "Q1"
and "Q2" read the parameters being shown on the
Channel 1 and Channel 2 output displays as
selected with the S command. "QX" and "QY"
read the X (RCOS Ø) and Y (RSIN Ø) BNC
outputs.
R {n}
If n is included, the R command sets the
reference input trigger mode. If n is absent, the
trigger mode is returned.
n Mode
0 ositive
1 Symmetric
2 Negative
S {n}
If n is included, the S command selects the
parameters shown on the Channel 1 and 2 analog
meters, output digital displays, and output BNC's.
If n is absent, the displayed parameter is returned.
n Channel 1 Channel 2
0 X Y
1 X Offset Y Offset
2 R Ø
3 R Offset Ø
4 X Noise Y Noise
5 X5 (D/A) X6 (D/A)
T m {,n}
The T command sets and reads the status of the
time constants. If m is "1", the pre time constant
is selected, if m is "2", the post time constant is
selected. The parameter m is required. If n is
included, the T command sets the selected time
constant. If n is absent, the setting of the selected
time constant is returned.
n Pre Time Constant (m=1)
1 1 mS
2 3 mS
3 10 mS
4 30 mS
5 100 mS
6 300 mS
7 1 S
8 3 S
9 10 S
10 30 S
11 100 S
n Post Time Constant (m=2)
0 none
1 0.1 S
2 1 S
U m {,n}
The U command sets and reads the unit's
calibration bytes. m is the address offset of the
byte, 0-511. If n is absent, the value of the
addressed calibration byte is returned. If n is
included, the addressed calibration byte is set to
the value of n, 0-255. The new value will be in
effect until the power is turned off or a reset
command is issued. Use of this command is not
recommended.
V {n}
If n is included, the V command sets the GPIB
SRQ (service request) mask to the value n (0-
255). If n is absent, the value of the SRQ mask is
returned.
W {n}
The W command sets and reads the RS232
character wait interval. If n is included, the SR530
will wait nx4 mS between characters sent over the
RS232 interface. This allows slow computer
interfaces to keep up. n can range from 0 to 255.
If n is absent, the wait value is returned. The wait
interval is set to 6 on power-up.
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