GPIB
4-22 370B User Manual
DeviceĆDependent Message Format
Device-dependent messages travel both ways between the instrument and
controller, and are used to:
Set instrument controls
Request and return the instrument status
Request, return, and send waveforms
Request and return results of other measurements
Most messages are sent as strings of ASCII characters; however, data represent-
ing sets of curves are sent as series of binary-coded numbers.
Commands are sent from the controller to the instrument. Each starts with a key
word called a header which is usually followed by an argument to further detail
the instruction. The key words used for command headers and arguments are
mnemonics related to specific instrument controls and functions. Multiple
commands can be sent in one message. Many command headers can be issued
with an attached question mark (?), identifying them as queries which prompt the
instrument for certain information.
Response to queried either contain information about instrument status or
measurement data. Generally, status messages are made up of the same key
words used for commands. The only device-dependent message not made up of
words or parts of words are those made up of curve data.
Each message ends with the message terminator, which was discussed earlier. In
most cases the controller or its language takes care of the message terminator and
it i s no longer a concern once it has been chosen and set.
Commands for the 370B Curve Tracer, like those for other Tektronix GPIB
instruments, follow the conventions of the Tektronix Standard Codes and
Formats. Each command starts with a key word header which is often followed
by one or more key word arguments to further specify the action to be taken. The
key words for commands were chosen to be as understandable as possible, while
still allowing a familiar use to shorten most of them to only a few characters.
Syntax is also standardized to make the commands easier to lean.
In most of this section, key words for headers and arguments are listed in a
combination of uppercase and lowercase letters. The instrument accepts any
abbreviated header or argument containing at least all the characters shown in
uppercase. We show them as uppercase for emphasis only. The 370B accepts
upper or lower case characters. In many cases, the commands may be expressed
in a variety of valid ways.
Command Message
Formats
To Next Page
Loading...