Ametek 7280 Instruction Manual page 203

IMODE [n] Current/Voltage mode input selector
n Input mode
0 Current mode off - voltage mode input enabled
1 Normal current mode enabled - connect signal to B input connector
2 Low noise current mode enabled - connect signal to B input connector
3 High bandwidth current mode enabled - connect signal to B input connector
If n = 0 then the input configuration is determined by the VMODE command.
If n > 0 then current mode is enabled irrespective of the VMODE setting.
LEN [n] Curve length control
The value of n sets the curve buffer length in effect for data acquisition. The
maximum allowed value depends on the number of curves requested using the CBD
command, and a parameter error results if the value given is too large. For this
reason, if the number of points is to be increased and the number of curves to be
stored is to be reduced using the CBD command, then the CBD command should be
issued first.
LF [n n ] Signal channel line frequency rejection filter control
1 2
The LF command sets the mode and frequency of the line frequency rejection (notch)
filter according to the following tables:
n Selection
1
0 Off
1 Enable 50 or 60 Hz notch filter
2 Enable 100 or 120 Hz notch filter
3 Enable both filters
n Notch Filter Center Frequencies
2
0 60 Hz (and/or 120 Hz)
1 50 Hz (and/or 100 Hz)
LOCK System lock control
Updates all frequency-dependent gain and phase correction parameters.
LR[.] Log Ratio output
In integer mode, the LR command reports a number equivalent to
1000×log(X/ADC1) where X is the value that would be returned by the X command
and ADC1 is the value that would be returned by the ADC1 command. The response
range is -3000 to +2079
In floating point mode, the LR. command reports a number equivalent to
log(X/ADC1). The response range is -3.000 to +2.079
LTS [n] Display on/off control
n Selection
0 Display off
1 Normal operation
M Curve acquisition status monitor
Causes the lock-in amplifier to respond with four values that provide information
concerning data acquisition, as follows:
Appendix F, ALPHABETICAL LISTING OF COMMANDS
F-11