IBM 7220, Instruction Manual

Page: 93 / 155

6-17
Chapter 6, COMPUTER OPERATION
XY[.] X, Y outputs
Equivalent to the compound command X[.];Y[.]
MAG[.] Magnitude
In fixed point mode causes the lock-in amplifier to respond with the magnitude value
in the range 0 to 30000, full-scale being 10000.
In floating point mode causes the lock-in amplifier to respond with the magnitude
value in the range +3.000E0 to +0.001E-9 volts or +3.000E-6 to +0.001E-15 amps.
PHA[.] Signal phase
In fixed point mode causes the lock-in amplifier to respond with the signal phase in
centidegrees, in the range ±18000.
In floating point mode causes the lock-in amplifier to respond with the signal phase in
degrees.
MP[.] Magnitude, phase
Equivalent to the compound command MAG[.];PHA[.]
RT[.] Ratio output
In integer mode the RT command reports a number equivalent to 1000 × 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.
In floating point mode the RT. command reports a number equivalent to X / ADC 1.
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 / ADC 1). The response range is -3.000 to +2.079.
NHZ.
Causes the lock-in amplifier to respond with the square root of the noise spectral
density measured at the Y output, expressed in volt/
√
Hz or amp/
√
Hz referred to the
input. This measurement assumes that the Y output is Gaussian with zero mean.
(Section 3.10). The command is only available in floating point mode.
This command is not available when the reference frequency exceeds 60 kHz.