Ametek 7280 Instruction Manual page 164

Chapter 6, COMPUTER OPERATION
DCB n
6-30
Bit Decimal value
0 1
1 2
2 4
3 8
4 16
5 32
6 64
7 128
8 256
9 512
10 1024
11 2048
12 4096
13 8192
14 16384
15 32768
Dual modes only:-
17 131072
18 262144
19 524288
20 1048576
21 2097152
The values of the selected curves at the same sample point are transferred as a group
in the order of the above table, separated by the chosen delimiter character and
terminated with the selected terminator. This continues until all the points have been
transferred.
NOTE: When transferring the Frequency curve, which is saved when bit 15 in the
CBD parameter is asserted, the instrument automatically reads the data for each
stored point in both frequency curves (i.e. the lower and upper 16 bits) and sends it
as a single data point.
Dump acquired curve(s) to computer in binary format
This command causes a stored curve to be dumped via the computer interface in
binary format, using two bytes per point. All curves other than the lower 16-bits of
the reference frequency curve (curve 15) use 16-bit 2's complement encoding, and all
data points are sent with the MSB first. The number of data bytes sent is therefore
equal to twice the current curve length. Each point is sent in fixed point mode, there
being no floating point version of the command, and hence if floating point values
are required the user may need to additionally store and read the Sensitivity curve
and then perform the correction in his own software. In order to achieve the
maximum transfer rate, no terminators are used within the transmission, although the
response is terminated normally at the end.
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 in Single Reference Mode, and 0 to 21 in the dual modes. If for
example CBD 5 had been sent, equivalent to asserting bits 0 and 2, then the X and
Output and range
X Output (±10000 FS)
Y Output (±10000 FS)
Magnitude Output (0 to +10000 FS)
Phase (±18000 = ±180°)
Sensitivity setting (3 to 27) + IMODE (0, 1, 2, 3 =
0, 32, 64, 128)
Noise (0 to +10000 FS)
Ratio (±10000 FS)
Log ratio (-3000 to +2000)
ADC1 (±10000 = ±10.0 V)
ADC2 (±10000 = ±10.0 V)
ADC3 (±10000 = ±10.0 V)
ADC4 (±10000 = ±10.0 V)
DAC1 (±10000 = ±10.0 V)
DAC2 (±10000 = ±10.0 V)
EVENT variable (0 to 32767)
Reference frequency (millihertz)
X Output (±10000 FS)
2
Y Output (±10000 FS)
2
Magnitude2 Output (0 to +10000 FS)
Phase Output (±18000 = ±180°)
2
Sensitivity setting (3 to 27) + IMODE
2
(0, 1, 2, 3 = 0, 32, 64, 128)