Ametek 7230 Instruction Manual page 114

Chapter 6, COMPUTER OPERATION
HC
M
DC[.] n
6-28
Halt curve acquisition
Halts curve acquisition in progress. It is effective during both single (data acquisition
initiated by TD command) and continuous (data acquisition initiated by TDC
command) curve acquisitions. The curve may be restarted by means of the TD, TDT
or TDC command, as appropriate. If an oscillator frequency and/or amplitude sweep
has been defined and linked to the curve buffer using the SWEEP command with a
parameter of 9, 10 or 11, then this sweep will be stopped as well.
Curve acquisition status monitor
Causes the lock-in amplifier to respond with four values that provide information
concerning data acquisition, as follows:
First value, Curve Acquisition Status: a number with five possible values, defined
by the following table:
First Value Significance
0 No curve activity in progress.
1 Acquisition via TD command in progress and running.
2 Acquisition via TDC command in progress and running.
5 Acquisition via TD command in progress but halted by HC
command.
6 Acquisition via TDC command in progress but halted by
HC command.
Second value, Number of Sweeps Acquired: This number is incremented each
time a TD is completed and each time a full cycle is completed on a TDC
acquisition. It is zeroed by the NC command and also whenever a CBD or LEN
command is applied without parameters.
Third value, Status Byte: The same as the response to the ST command. The
number returned is the decimal equivalent of the status byte and refers to the
previously applied command.
Fourth value, Number of Points Acquired: This number is incremented each time
a point is taken. It is zeroed by the NC command and whenever CBD or LEN is
applied without parameters.
Dump acquired curve(s) to computer
The operation of this command depends on whether data has been stored into the
Standard or Fast Mode curve buffers.
Standard Mode
In fixed point mode, causes a stored curve to be dumped via the computer interface
in decimal format.
In floating point mode the SEN curve (bit 4 in CBD) must have been stored if one or
more of the following outputs are required in order that the lock-in amplifier can
perform the necessary conversion from %FS to volts or amps:- X, Y, Magnitude,
Noise. Similarly, if the dual reference or harmonic modes are active then the SEN2
curve (bit 21 in CBD) must have been stored in order to perform a similar conversion
from %FS to volts or amps for X2, Y2 and Magnitude2.
One curve at a time is transferred. The value of n is the bit number of the required
curve, which must have been stored by the most recent CBD command. Hence n can
range from 0 to 16, or 0 to 21 if a dual mode is active. If for example CBD 5 had