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Chapter 3
Configuring and Using Your Hardware
Setting the Data Transfer Mode
The two GPIB extenders in your extension system must use the same data transfer mode.
To use buffered mode, set DIP switch 1 to the ON position, as shown in Figure 3-1. To use
unbuffered mode, set DIP switch 1 to the OFF position.
Figure 3-1.
DIP Switch Setting for Buffered Mode
HS488 Mode
The GPIB extender can handle data transfers using the HS488 protocol. HS488 transfers data
between two or more devices using a noninterlocked handshaking protocol. You can use HS488
to transfer data at rates higher than rates possible using the IEEE 488 protocol. For more
information about HS488, refer to Appendix B,
Introduction to HS488
.
Selecting an HS488 Mode
To select an HS488 mode, refer to the following descriptions of each mode.
HS488 Disabled
If you disable HS488, the GPIB extender sources and accepts data using a three-wire handshaking
protocol, even if both the Talker and Listener can transfer data using the HS488 protocol.
HS488 Enabled
After the Talker indicates that it wants to issue HS488 transfers, HS488 is enabled and the GPIB
extender accepts data using the HS488 protocol. Also, when talking, the GPIB extender always
tries to use the HS488 mode. In HS488 mode, FIFO buffers buffer data during HS488 transfers,
even if the data transfer mode is set to unbuffered. When you use the HS488 protocol with the
GPIB extender, you should set the GPIB cable length to 5 m for both the local and the remote
system. To do so, use your IEEE 488.2 software configuration utility.
Setting the HS488 Mode
The two GPIB extenders in your extension system do not need to use the same HS488 mode.
However, the system uses the maximum data transfer rate when both sides in your extension
system use HS488.
PARALLEL POLL IMMEDIATE
H
S
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88
ENABLE
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FER
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OFF
ON
