Chapter 3
Technical Information
© National Instruments Corp.
3-5
GPIB-PRL User Manual
If switch 2 is ON and switch 3 is OFF, the GPIB-PRL will not send out a
listen address but will be the System Controller and will assert IFC*. This
mode can be used if the GPIB-PRL is connected to a listen-only device
which does not require addressing. In the above mentioned modes the
GPIB-PRL will be programmed as a talk-only device.
If switch 2 is OFF and switch 3 is ON, the GPIB address on the switch will
be considered the GPIB-PRL talk address. In this mode the GPIB-PRL will
not be the System Controller and it does not have the ability to address itself
or any other GPIB device. There must be a GPIB controller on the bus
which will address the GPIB-PRL to talk and another GPIB device to listen.
If the parallel port signal INIT* is asserted, it will cause the GPIB-PRL to
clear its internal buffer. Also, either the SDC or DCL command (mode
dependent) will be sent over the GPIB to initialize the GPIB device.
The interface signal descriptions and timing relationships for the parallel
port while in P Mode are shown in the following table.
