Allen-Bradley 1747-OC Series, User Manual

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1747-UM001A-US-P - March 2000
5-2 Defining System Settings
PCI/PnP (PCI) interrupts:
•
are routed by BIOS to the IRQs (Interrupt Requests) defined as PCI in
BIOS.
•
can be shared by multiple PCI devices. BIOS tries to allocate one IRQ
for each PCI/PnP device that requires an interrupt. If there are not
enough IRQs defined as PCI/PnP, BIOS assigns the same IRQ to more
than one device.
•
are low true interrupts.
How ISA/EISA interrupts and PCI/PnP interrupts interact
PCI interrupts are automatically chosen from those defined by default as
PCI/PnP or PCI:
Within an open controller system:
•
PC Cards in a PCMCIA interface module always use ISA/EISA
interrupts
•
the 1747-OCKTX, -OCKTXD channels can use ISA/EISA interrupts or
PCI/PnP interrupts, depending on how you set the jumpers on the
module
The PCI resources are assigned independently of the operating system being
run. The PCI resources only change if you modify the hardware in the open
controller system.
The open controller comes with a diagnostic/utility disk that includes an
ocpci
utility (
ocpci.exe
for DOS and
ocpci_nt.exe
for Windows
NT). The
ocpci
utility reports the currently assigned memory addresses
and PCI interrupts for all the open controller option modules.
This Open Controller: Defines these IRQs: As:
1747-OCE 5, 9, 10 PCI/PnP
1747-OCF 5, 9, 10, 11 PCI
The 1747-OCF defines IRQ 11 as a PCI interrupt to accommodate the
embedded I/O scanner, which uses a PCI interrupt instead of an ISA
interrupt, as in the 1747-OCE.
Important: If you are using a 1747-OCF, you must use
ocpci
utility
version 2.0 or later, provided on your utilities disk. Earlier
versions of this utility will not work on the 1747-OCF.