Ametek 7280 Instruction Manual page 173

LF 0 0 Turn off line frequency rejection filter
OA. 1.0E0 Set oscillator amplitude to 1.0 V rms
OF. 100.0 Set initial oscillator frequency to 100 Hz so that
AQN runs correctly
SEN 27 Set sensitivity to 1 V full-scale
TC 12 Set time constant to 10 ms
AQN Auto-Phase
FASTMODE 0 Used to set the Analog Outputs to normal
update rate, allowing faster frequency sweep rates.
The next group of commands set up the frequency sweep:
FSTART. 100.0 Set initial oscillator frequency to 100 Hz
FSTOP. 1000.0 Set final oscillator frequency to 1000 Hz
FSTEP. 10 1 Step size = 10 Hz, linear law
SRATE. 0.05 50 ms per step
There will therefore be 91 points (100 Hz to 1000 Hz inclusive in 10 Hz steps). Now
specify the curve storage:
NC Clear and reset curve buffer
CBD 32796 Stores Magnitude, Phase, Sensitivity and Frequency
(i.e. bits 2, 3, 4 and 15)
LEN 91 Number of points = 91. The oscillator step size and
this parameter need to be chosen so that the curve buffer will
include the full frequency sweep. With 10 Hz steps from
100 Hz to 1000 Hz, there will be 91 points.
STR 50 Store a point every 50 ms - must match
SRATE parameter
SWEEP 9 Sets frequency sweep to be linked to curve buffer acquisition
The data may now be acquired by issuing the command:
TD Starts sweep and curve acquisition
The frequency sweep starts and the magnitude and phase outputs are recorded to the
curve buffer. As it runs the M command reports the status of the acquisition, and
once this indicates it is complete (i.e. parameter 1 = 0, parameter 2 = 1), the acquired
data may be transferred to the computer using:
DC. 2 Transfers Magnitude curve
DC. 3 Transfers Phase curve
DC. 15 Transfers Reference frequency
Chapter 6, COMPUTER OPERATION
6-39