Teledyne LeCroy X-STREAM OSCILLOSCOPES Remote Control - Manual (Page 19)

WM-RCM-E Rev D ISSUED: February 2005
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Control by GPIB
Talk, Listen, or Control
You can control your X-Stream DSO remotely, using the General Purpose Interface Bus (GPIB). GPIB is
similar to a standard computer bus. But while the computer interconnects circuit cards by means of a
backplane bus, the GPIB interconnects independent devices (oscilloscopes and computers, for example) by
means of a cable bus. GPIB also carries both program and interface messages.
Program messages, often called device dependent messages, contain programming instructions, measurement
results, oscilloscope status and waveform data.
Interface messages manage the bus itself. They perform functions such as initialization, addressing and
“unaddressing” of devices, and the setting of remote and local modes.
On the one hand, devices connected by GPIB to your X-Stream DSO can be listeners, talkers, or controllers. A
talker sends program messages to one or more listeners, while a controller manages the flow of information on
the bus by sending interface messages to the devices. The host computer must be able to play all three roles.
For details of how the controller configures the GPIB for specific functions, refer to the GPIB interface
manufacturer’s manual.
On the other hand, the X-Stream DSO can be a talker or listener, but NOT a controller.
Much of the material in this chapter is general to all GPIB systems, but where detailed instructions and
program fragments are provided in this manual, they are based on National Instruments hardware and
software, and on some form of BASIC language. Where INCLUDES are mentioned, this points to the need to
couple the programming language to the GPIB by including some drivers. The National Instruments manuals
explain this. Variables ending with % are integers, and variables ending with $ are strings, in accordance with
the practice in some BASIC languages. The entire system is of course compatible with any hardware and
software based on IEEE-488.2, and any programming language can be used if it can be linked to GPIB.