Siemens SIMATIC PANEL PC 877 - Manual (Page 218)

Detailed descriptions
17.2 Bus board
SIMATIC Panel PC 877
17-26
Operating instructions, Release 07/2006, A5E00877780-01
17.2.3 Exclusive PCI hardware interrupt
Applications demanding a high-performance interrupt require a high-speed hardware
interrupt reaction. The PCI hardware interrupt should be used only by one resource in order
to ensure high-speed reaction of the hardware. This can be forced by appropriate setting in
the system BIOS.
Setting up a reserved interrupt on the device
A reserved interrupt can only be set and used for PCI slots 2 and 4. Further reserved
interrupts for use on the slots are not available.
A reserved interrupt cannot be used on any of the PCI slots in the basic configuration. In
order to set up a reserved interrupt, you first need to disable the functions on the
motherboard 1) . This is possible for PCI slots 2 and 4.
In order to set up a reserved interrupt on PCI slot 2, you need to disable USB Controller B
(this is the external USB port at the top) in the BIOS.
In order to set up a reserved interrupt on PCI slot 4, you need to disable USB 2.0 Controller
in the BIOS (all USB ports are now operating in USB 1.1 mode) and (if installed in the
device) the PROFIBUS.
1) For information on how to disable motherboard functions, refer to the chapter dealing with
the BIOS setup.
Assigning a reserved interrupt in the BIOS Setup
With the factory setting of the system BIOS, the interrupts are automatically assigned to the
slots.
Depending on the system configuration, several slots may be assigned the same interrupt.
Here we refer to interrupt sharing.
The special feature of the BIOS of the device is that interrupts can be set selectively and
assigned to the interrupt channels of the slots. Here we refer to a reserved interrupt.
Specific interrupts can be assigned to slots in the Advanced menu of the BIOS setup.
To do so:
To enable the use of a reserved interrupt at PCI slot 2, assign PCI IRQ Line 2 the required
free interrupt, and all other PCI interrupt channels (channels 1, 3, 4) another interrupt.
To enable the use of a reserved interrupt at PCI slot 4, assign PCI IRQ Line 4 the required
free interrupt, and all other PCI interrupt channels (channels 1, 2, 3) another interrupt.
To do this, open the Advanced menu of the BIOS setup and then PCI Configuration. In this
menu you can assign the specific PCI IRQ channels to the respective interrupts.
You cannot assign interrupts that are already used by the system.
If you assign an interrupt which is already in use by the system or is reserved, the system
marks it with a yellow star.
➜ May not be used.
Interrupts not reserved by the system can be assigned twice.