Siemens SIMATIC Rack PC 840 V2 Operating Instructions Manual page 135

"PCI IRQ line" field
Figure 16-17 The PCI IRQ line field
Disabled
AutoSelect
3 to 15
Assignment of the PCI IRQ channels to the PCI slots.
Rack PC 840
Module
interrupt
(Pin No.)
INT - A (A6)
INT - B (B7)
INT - C (A7)
INT - D (B8)
Bold letters indicate the master interrupt of the slot module
SIMATIC Rack PC 840 V2
Operating Instructions, Edition 05/2006, A5E00248055-04
No interrupt possible for the selected PCI IRQ channel
Plug and Play mechanism in BIOS selects unassigned interrupts and allocates them
to the on-board PCI devices.
The selected PCI IRQ channel is assigned permanently to the selected interrupt.
You should only select this setting if this is specified in the documentation for your
application.
PCI modules interrupt assignment (PCI IRQ) in:
Slot 1 Slot 2
channel 1 channel 2 channel 3 channel 4 channel 1 channel 2 channel 3
channel 2 channel 3 channel 4 channel 1 channel 2 channel 3 channel 4
channel 3 channel 4 channel 1 channel 2 channel 3 channel 4 channel 1
channel 4 channel 1 channel 2 channel 3 channel 4 channel 1 channel 2
Slot 3 Slot 4 Slot 5
Detailed descriptions
16.5 BIOS Setup
Slot 6 Slot 8
16-37