Manual

WM-RCM-E Rev D ISSUED: February 2005

HAPTER

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.