Definite Length Arbitrary Block Data Format - Tabor Electronics 5064 User Manual

"#"
Start of
Data Block
Number of
Digits to Follow
Figure ‎ 5 -1, Definite Length Arbitrary Block Data Format
Transfer of definite length arbitrary block data must terminate with the EOI bit set. This way, carriage-return
(CR – 0dH) and line feed (LF – 0aH) characters can be used as waveform data points and will not cause
unexpected termination of the arbitrary block data.

<binary_block>
The waveform data is made of 16-bit words however, the GPIB link has 8 data bas lines and accepts 8-bit
words only. Therefore, the data has to be prepared as 16-bit words and rearranged as two 8-bit words
before it can be used by the 2074 as waveform data points. The following description shows you how to
prepare the data for downloading to the 2074. There are a number of points you should be aware of before
you start preparing the data:
1. Each channel has its own waveform memory. Therefore, make sure you selected the correct active
channel before you download data to the generator
2. Waveform data points have 16-bit values
3. Data point range is 0 to 65,535 decimal
4. Data point 0 to data point 65,535 corresponds to full-scale amplitude setting.
Figure 5-2 shows how to initially prepare the 16-bit word for a waveform data point. Data has to be further
manipulated to a final format that the instrument can accept and process as waveform point.
MSB
D15 D14 D13
Figure ‎ 5 -2, 16-bit Initial Waveform Data Point Representation
Figure 5-3 shows the same 16-bit word as in Figure 5-2, except the high and low bytes are swapped. This
is the correct format that the 2074 expects as waveform point data. The first byte to be sent to the generator
non-zero
ASCII digit
ASCII digit
Byte Count:
2 x Number of
Points
Represents waveform data.
high-byte
D12 D11 D10 D9
low byte
(binary)
2 Byts Per
Data Point
low-byte
D8 D7 D6 D5 D4
high byte
(binary)
LSB
D3 D2 D1 D0
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