3.27.8 Addressed Commands
but the control knob will be inoperative so no settings
Addressed commands are used to command a device can be changed. the
real
time (Trigger,
to perform designated actions, Addressed commands Hold, Return) and the Counter key will function just as
are
recognized
only when
the
instrument
is
addressed
in local mode. When the instrument is in the remote
as a listener, Addressed commands performed by the
mode, the GPlB interface input has priority over any front
Model 75 are:
panel control, and the Control knob is completely
ignored. Therefore, as long as the GPIB interface is con-
'.
(GTL)
-
Commands
the
75
tinuously supplied with data, the keyboard will appear
go to the local mode.
to be inoperative to the user.
2. Selective Device Clear (SDC)
-
Resets the Model
75 to its default conditions.
Line 2 of the LCD always shows the state of the GPlB
interface after scanning the last string (see paragraph
3.
Execute
Trigger (GET)-
"pan
receipt
Of
the
3.28.9). In the lower right corner, several characters may
GET, the programmed settings are error checked.
appear:
If no error is detected, the control information is
transferred to the waveform generator circuit,
'R'
=
Remote
followed bya trigger. In order
toensure system syn-
'L'
=
Addressed to listen
chronization with a GET, the Model 75 will not
com-
'T'
=
Addressed to talk
plete the handshake sequence until it has finished
1
'Q'
=
Request of service because of selected SRQ
execution of the GET. mode
3.27.9 Data Transfer
In addition to accepting programming characters, the
Model 75 will transmit status and waveform information
over the bus. To program the instrument, first send the
listen address (with ATN on), followed by the program-
ming data (in ASCII, with ATN off). The instrument
accepts the data as fast as possible (at approximately
120pslcharacter), until either 64 characters are received
or there is a pause during the transfer of data. At the time,
the entire string of received characters is scanned by
the Model 75, which carries out the scan and accepts
the next
64character string. Whenever the Model 75 is
finished scanning a string, the display will show the last
parameter of the string and thecurrent
statusof theGPlB
interface. If the EOI line is asserted while sending a
character to the Model 75, the currently programmed
terminator character will be put into the input string
following the character with the EOI.
3.28 MODEL 75 GPlB PROGRAMMING
This section describes the remote operation of the Model
75. For general GPlB programming information, refer to
paragraph 3.27.
Paragraphs 3.28.1 through 3.28.5 provide background
information and should be read before attempting to pro-
gram the Model 75. Table 3-2 is a programming reference
guide giving detailed descriptions of each programming
character and information for writing actual statements
to the Model 75.
3.28.1 General Programming Information
Line 1 is the parameter and special message readout.
An asterisk(*) to the left of the parameter indicates that
an execute has not been sent.
The front panel display is externally programmed by
sending any
ASCII character between single or double
quotes, such as 'test string' or "test string".
The Model 75 is programmed by sending ASCII coded
characters to the instrument (see table 3-2 and Appen-
dix A).
3.28.2 Characters
There are 5 types of characters that can be sent over
the GPlB bus. These are:
1. Alphabetic characters
-
'A' through
'Z'
(except
'E').
These select action or parameter commands. Both
upper and lower case characters are accepted.
2. Numeric
characters(Suffix) -These are '0' through
'9', 'E'(exponent),
'
-
'(negative),
'
+
'(positive), and
the decimal point. They control the selected
parameter.
3. Special characters; The instrument will display any
set of characters within single or double quotes,
such as 'string'. The pound sign
(#)
initiates high
speed data transfer (see paragraph 3.28.7).
4. Terminator
-
Designates the end of a character
string. Initially, this is line feed (LF).
5. Nonprogramming characters
-
These are
characters not in one of the previous described
classes. They have no effect on programming and
When the Model 75 is in remote mode, the menu and soft may be interspersed freely after any programming
keys can
still be used toexamine the instrument settings,
character other than
'X'.
Scans
by
ArtekMedia
O
2006
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