Technical data

Introduction to Programming 3
Agilent Infiniium 9000 Series Oscilloscopes Programmer's Reference 53
Communicating with the Oscilloscope
Computers communicate with the oscilloscope by sending and receiving
messages over a remote interface, such as a GPIB card (must order the
N4865A GPIB- to- LAN adapter) or a Local Area Network (LAN) card.
Commands for programming normally appear as ASCII character strings
embedded inside the output statements of a "host" language available on
your computer. The input commands of the host language are used to read
responses from the oscilloscope.
For example, the VISA COM library provides the WriteString() method for
sending commands and queries. After a query is sent, the response can be
read using the ReadString() method. The ReadString() method passes the
value across the bus to the computer and places it in the designated
variable.
For the GPIB interface, messages are placed on the bus using an output
command and passing the device address, program message, and a
terminator. Passing the device address ensures that the program message
is sent to the correct GPIB interface and GPIB device.
The following WriteString() method sends a command that sets the channel
1 scale value to 500 mV:
myScope.WriteString ":CHANNEL1:SCALE 500E-3"
The VISA COM library setup is explained on the following pages.
NOTE
Use the Suffix Multiplier Instead
Using "mV" or "V" following the numeric voltage value in some commands will cause
Error 138 - Suffix not allowed. Instead, use the convention for the suffix multiplier as
described in Chapter 5, “Message Communication and System Functions,” starting on page
99.