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Chapter 6, COMPUTER OPERATION
6.4.12 Front Panel
LTS [n] Lights on/off control
The value of n controls the front panel LEDs and LCD backlights according to the
following table:
n Selection
0 All lights off
1 Normal operation
6.4.13 Default Setting
ADF Default Setting command
This command will automatically set all the instrument controls and displays to the
factory set default values. However, if the command is used when the interface
parameters are at values other than their default settings, then communication will be
lost.
6.5 Programming Examples
6.5.01 Introduction
This section gives some examples of the commands that need to be sent to the lock-in
amplifier for typical experimental situations.
6.5.02 Basic Signal Recovery
In a typical simple experiment, the computer is used to set the instrument controls and
then to record the chosen outputs, perhaps as a function of time. At sampling rates of
up to a few points per second, there is no need to use the internal curve buffer. The
commands to achieve this would therefore be similar to the following sequence:
IE 2 Set reference to external front panel input
VMODE 1 Single-ended voltage input mode
FET 1 10 MΩ input impedance using FET stage
AUTOMATIC 1 AC Gain control automatic
FLOAT 1 Float input connector shell using 1 kΩ to ground
LF 0 Turn off line frequency rejection filter
ASM Auto-Measure (assumes reference frequency > 1 Hz)
TC 12 Set time constant to 200 ms, since previous ASM changed it
Then the outputs could be read as follows:
X. Reads X output in volts
Y. Reads Y output in volts
MAG. Reads Magnitude in volts
PHA. Reads Phase in degrees
FRQ. Reads reference frequency in hertz