Options and
Accessories-2230
Operators
CURVE
<space>
% <Binary Count
MSB>
<Binary
Count
LSB>
<Binary
Data>
<Checsum>
<Termi-
nator>
Where:
CURVE
%
<Binary
Count
MSB>
<Binary Count
LSB>
<Binary
Data>
<Checksum>
is
a literal string indicating that
curve data follows.
is
used
as
a header character
to show the start of a binary
block.
is
the most-significant byte of
the two-byte Binary Count.
Binary Count
is
the length of
the waveform,
in
bytes, plus
the one-byte checksum.
is
the least-significant byte of
the Binary Count.
is
made
up
of 256, 512, 1024,
2048, or 4096 data points.
Each
data point
is
either a
1-
byte
(8
bits) or 2-byte
(16
bits)
representation of
each
digitized value.
is
the two's-complement of the
modulo 256
sum
of the
preceding data bytes
and
the
binary count.
The
Checksum
is
used
by
the controller program
to verify that
all
data values
have
been
received correctly.
Table 7
-17
illustrates the data transferred for a
4096-point, 8-bit, binary-encoded waveform. The waveform
data-point values vary with the signal amplitude.
Table 7-18 illustrates the data transferred for a
4096-point, 16-bit (averaged), binary-encoded waveform.
Hexadecimal Encoding
With HEXadecimal waveform data encoding, characters
representing
an
8-bit or 16-bit data point
are
sent
in
a
fixed ASCII hexadecimal format. There
are
no
delimiters
(commas) between data points. Data format
is
very similar
to BINary format, with the following exceptions:
7-22
Table 7-17
Typical 8-Bit Binary-Encoded Waveform Data
Byte Contents Decimal
1
C
67
2 u
85
3 R
82
4 V
86
5 E
69
6
<SP>
32
7
% 37
8
<Bin
Count
MSB>
16a
9
<Bin
Count
LSB>
01a
10 1st
Pt
d1
11
2nd
Pt
d2
4105
4096th Pt
d409s
4106
<Checksum>
chk
4107t
<CR>
13
4108(
<LF>
10
8
(1001
16
or
4097
10
)
hAU
RS-232-C
or
GPIB
with
TERM = LF/EOI.
CRS-232-C
with
TERM = CR-LF.
GPIB EOI
(1
=Asserted)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
When
TERM=EOI
0
1
1.
The
curve header
is
"CURVE
#H"
instead of
"CURVE%".
2.
Each
data point
is
two ASCII hexadecimal characters
for 8-bit transfers
and
four ASCII hexadecimal characters
for 16-bit transfers.
3.
The
byte count
is
sent
as
four successive ASCII hex-
adecimal characters, but the
value
of the byte count
is
identical to a comparable BINary transfer.
4.
The
checksum
is
sent
as
two successive ASCII hex-
adecimal characters.
--
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