Detailed descriptions
16.2 Bus board
SIMATIC Rack PC 840 V2
Operating Instructions, Edition 05/2006, A5E00248055-04
16-13
16.2
16.2
Bus board
16.2.1
Layout and principle of operation
The bus board is designed as a link between the motherboard and the expansion modules. It
is mounted by means of four screws.
The bus board has seven PCI slots and five long format ISA slots. Ten expansion modules
can be inserted simultaneously according to ISA specification (Rev. 3.1) and PCI
specification (Rev. 2.0). All PCI slots are master–capable. The expansion modules are
powered via the link between the bus board and the motherboard and via the auxiliary ATX
contact directly from the power supply unit.
Figure 16-3 Bus board
Assignment of the PCI IRQ channels to the PCI slots.
Rack PC 840 V2 PCI modules interrupt assignment (PCI IRQ) in:
Module interrupt
(Pin No.)
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5
Slot 6
Slot 8
INT – A (A6)
channel 1 channel 2 channel 3 channel 4 channel 1 channel 2 channel 3
INT – B (B7)
channel 2 channel 3 channel 4 channel 1 channel 2 channel 3 channel 4
INT – C (A7)
channel 3 channel 4 channel 1 channel 2 channel 3 channel 4 channel 1
INT – D (B8)
channel 4 channel 1 channel 2 channel 3 channel 4 channel 1 channel 2
Bold letters in the table means: Master interrupt of the slot module
