High Speed Binary Waveform Transfer; Reading Waveforms From The Model 75; Programming Reference Guide - Wavetek 75 Instruction Manual

the end of the waveform. Each time an 'L' is sent followed
by a Y value the waveform address is incremented.
Sending a 'K' followed by an address only affects the
transfer of waveform data and does not affect the
waveform directly. Any part of the 81 92 point waveform
memory can be written to whether or not it is between
the current start and stop addresses (active waveform).
For example, sending a 10 step ramp from X
= 20
to
X
=
29 would be accomplished by sending the following
to the Model
75;
3.28.7 High Speed Binary Waveform Transfer
With software versions 2.1 4 and later, waveform data
can be sent to the Model 75 in binary form at a rate of
approximately 14.5 kbytesls (each waveform point takes
2
bytes) from a fast GPIBcontroller such as the Wavetek
Model 6000. In this way a 2048 point waveform can be
sent to the Model 75 in 280 ms. To check the software
version number, press RSET from the Setup menu (do
not press execute unless you want to reset the instru-
ment) and read the top line of the display.
To send a block of waveform data, send an ASCll
"#"
($23), then a 2 byte binary beginning address with the
most significant byte (MSB) first, then a
2
byte binary
word count (MSB first), then the two byte data words
(MSB first). The beginning address and the word count
must be less than 81 92. The word count is the number
of waveform data points to be changedand must exactly
correspond to the number of data words. Each data word
isa two byte binaryword representing a number between
0
and
4095.
The actual Y-value of each data point is
2048
less than thevalueof thedata word. For example, adata
word of 1 corresponds to as Y-value of
-
2047.
The Model
75
must be completely finished processing
all previous commands and any numeric input must be
terminated prior to receiving the "#" character.The best
way to insure this is to send a terminator character
(typically LF) and a GET to the Model 75 prior to the
"#".
If the trigger cannot be tolerated, besure that the Model
75
has had enough time to processes all previous
commands before sending the "#".
If the beginning address or the word count are outside
the allowable range, or one half second elapses without
receiving any data, the high speed transfer will be
aborted. Any data received after this will be interpreted
as ASCII charactersandmay cause the Model
75
to act
unpredictably. Because of this low tolerance for errors,
the high speed waveform transfer method should be
used with extreme care.
3.28.8 Reading Waveforms From the Model 75
Reading waveform data from the Model
75
to a computer
is accomplished by setting the talk mode to
7
by sending
an 'XT7' and then reading successive data values (Y
values)from the Model 75. Datavalues are read starting
at a location specified by sending a 'K' followed by the
address(Xvalue) of the first point. Each time a data value
is read, the waveform address is incremented. Neither
sending a 'K' followed by an address nor reading a data
value has any direct effect on the wavedform output.
3.28.9 Programming Reference Guide
Table
3-2
can be used as a programming reference guide
when sending commands to the Model 75. It describes
each programming character and which numeric
characters are to be used toprogram parametervalues.
Before attempting to use this guide, read paragraphs
3.28.1 through 3.28.5.
When programming the Model 75, keep in mind that at
initial power up, the following remotesettings have been
defaulted.
Function ASCII Character Default Setting
GPlB ADRS
SRQ Mode
Talk Mode
Terminator
Bit Switch
1
0
10
Scans by Artekhledia O 2006