Agilent Technologies Infiniium 90000 Q-Series, Programmer'S Manual

Page: 53 / 1186

Introduction to Programming
3
Agilent Infiniium 90000 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 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.
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.
N O T E
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.