Introduction to GPIB Programming. Agilent Technologies 8712ES, 8714ET, 8714ES, 8712ET

Introduction to GPIB Programming

Introduction to GPIB Programming

Introduction to GPIB Programming

GPIB—the general purpopse interface bus—is a high-performance bus that connects individual instruments and computers together to make integrated test systems. The bus and its associated interface operations are defined by the IEEE 488.1 standard. The IEEE 488.2 standard defines the interface capabilities of instruments and controllers in a measurement system, including some frequently used commands.

GPIB cables provide the physical link between devices on the bus. There are eight data lines on each cable that are used to send data from one device to another. Devices that send data over these lines are called

Talkers. Listeners are devices that receive data over the same lines.

There are also five control lines on each cable that are used to manage traffic on the data lines and to control other interface operations.

Controllers are devices that use these control lines to specify the talker and listener in a data exchange. When a GPIB system contains more that one device with controller capabilities, only one of the devices is allowed to control data exchanges at any given time. The device currently controlling data exchanges is called the Active Controller.

Also, only one of the controller-capable devices can be designated as the

System Controller, the one device that can take control of the bus even if it is not the active controller. The network analyzer can act as a talker, listener, active controller or system controller at different times.

GPIB addresses provide a way to identify devices on the bus. Each device on the bus must have a unique address. The active controller uses GPIB addresses to specify which device talks and which device listens during a data exchange. Device addresses are set on each device using either a front-panel key sequence or a rear-panel switch.

To set the GPIB address on the analyzer, use the softkeys located in the

SYSTEM OPTIONS analyzer is 16.

GPIB menu. The factory default address for the

1-2 Programmer’s Guide

NOTE

Introduction to GPIB Programming

Introduction to GPIB Programming

Throughout this manual, the following conventions are used:

• Square brackets ( [ ] ) are used to enclose a keyword that is optional or implied when programming the command; that is, the instrument will process the command to have the same effect whether the option node is omitted or not.

• Parameter types ( < > ) are distinguished by enclosing the type name in angle brackets.

• A vertical bar ( | ) can be read as “or” and is used to separate alternative parameter options.

• A HARDKEY is a labeled button on the instrument front panel.

• A Softkey is one of the eight unlabeled buttons along the right side of the instrument display. The function of each Softkey is indicated next to the Softkey on the instrument display.

Programmer’s Guide 1-3