Chapter 3: Remote Operation; Gpib Address; Basic Gpib Concepts; Data And Interface Messages - Newport LDC-3706 Series User Manual

This chapter is an overview of the remote operation of the LDC-3706 Laser Controller.

Fundamentals of Remote Operation

Command Syntax
Test and measurement equipment with remote operation capability will generally communicate
through either GPIB or USB interfaces. GPIB (General Purpose Interface Bus) is the common name
for ANSI/IEEE Standard 488.2 1987, an industry standard for interconnecting test instruments in a
system. USB (Universal Serial Bus) is the common serial communication protocol used by most
computers. Everything that can be done from the front panel can also be done remotely, and in
some cases, with more flexibility. The following sections explain the fundamentals of operating the
LDC-3706 Laser Controller remotely through either the GPIB or USB computer interface.

GPIB Address

The talk and listen addresses on the LDC-3706 are identical. This GPIB address is read locally by
pressing the LOCAL button in the COMM section of the front panel until the GPIB Address is
displayed on one of the dot matrix displays. The instrument comes from the factory configured with
the GPIB address set to 1. The LDC-3706 instrument's GPIB address can be changed locally (via the
front panel). A procedure for changing the address can be found in the section changing the GPIB
Address.

Basic GPIB Concepts

The information in this section is normally not necessary to successfully operate the LDC-3706
instrument through its GPIB interface because the host computer's GPIB controller usually handles
the details. However, it is a useful introduction to understanding GPIB.

Data and Interface Messages

GPIB devices communicate with each other by sending data and interface messages. Data contains
device-specific information such as programming instructions, measurement results, and instrument
status. Each device has an address number, and ignores all data traffic not addressed to it.
Depending on its content, data is often called a "device dependent message" or a "device dependent
command". Interface messages manage the bus, with functions such as initializing the bus and
addressing or un-addressing devices. In addition, some individual bus lines are designated for this
purpose.
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Remote Operation
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Chapter 3:
LDC-3706 Series Laser Controller