Format for Data Transfer
There are three formats for transferring waveform data over the remote
interface. These formats are WORD, BYTE, or ASCII.
WORD and BYTE formatted waveform records are transmitted using the
arbitrary block program data format specified in IEEE-488.2. When you use
this format, the ASCII character string "#8 <DD...D>" is sent before the actual
data.
The <D>’s are eight ASCII numbers which indicate how many data bytes will
follow.
For example, if 8192 points of data are to be transmitted, the ASCII string
#800008192 would be sent.
BYTE Format
In BYTE format, the seven least significant bits represent the waveform data.
This means that the possible range of data is divided into 128 vertical
increments. The most significant bit is not used. If all "1"s are returned in
the seven least significant bits, the waveform is clipped at the top of the
screen. If all "0"s are returned, the waveform is clipped at the bottom of the
screen (see figure 35-1).
Figure 35-1
Byte Data Structure
The data returned in BYTE format is the same for either Normal or Average
acquisition types. The data transfer rate in this format is faster than the
other two formats.
WAVeform Subsystem
Format for Data Transfer
35-4