National Instruments GPIB-140A User Manual - page 21
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4-1
4
Theory of Operation
This chapter describes how the GPIB extender circuitry operates.
This chapter assumes that you are familiar with GPIB. If you are a first-time user or if you would
like to review the basics about GPIB, refer to Appendix A,
GPIB Basics
.
Figure 4-1 shows the five layers of a GPIB extender. To form a complete link, you can connect
each layer to the corresponding layer of another extender at the remote side.
Figure 4-1.
GPIB Extender Block Diagram
Message Interpreter
Layer
Message Interpreter
Layer
Packet Translation
Layer
Packet Translation
Layer
Link Management
Layer
Link Management
Layer
Parallel-to-Serial
Conversion Layer
Physical Layer
GPIB BUS #2
GPIB BUS #1
GPIB EXTENDER
GPIB EXTENDER
Transmission
Medium
Physical Layer
Parallel-to-Serial
Conversion Layer