Octagon PC-500, User Manual

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10-1
PC-500 user’s manual IRQ routing and opto IRQs
Chapter 10:
IRQ routing and opto IRQs
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Interrupt routing
The PC-500 provides a flexible method of enabling, disabling, and
routing system interrupts via an “in system” programmable logic device.
The logic device not only reduces the number of physical jumpers, but it
also reduces the possibility of choosing the incorrect jumper configura-
tion. For example, upon configuration the electronic jumpers remain set
until they are reprogrammed for a different configuration.
This device also allows some of the PC/104 bus interrupts and some of
the on-board generated interrupts to be routed to other IRQs of the
programmable interrupt controller. This routing matrix requires the
user to run the SETIRQ utility program to update the routing matrix
with the desired IRQ routes.
In addition to IRQ routing, the I/O range select A and select B bits can
be set so that the base addresses in COM5, EZ I/O, and COM3 through
COM5 IRQ status registers can be moved to different locations. These
can also be read at I/O address 0A9h bits 4 and 5.
See also the SETIRQ.DOC file in the \IRQ directory on the PC-500
utility disk for more information. The utility disk contains several ISP
files to program into the matrix. If these are not sufficient, call
Octagon’s Technical Support at 303-426-4521 for new ISP files that may
have become available.
Note If an output is not routed as a signal, then the output or destination is
neither driven high nor low, but is in a high impedance mode.
Note When you program a new IRQ routing matrix, the printer port must be
set to bi-directional mode. Also, any field devices connected to the
printer port must be disconnected.