Siemens SIMATIC PANEL PC 877 - Manual (Page 248)

Detailed descriptions
17.6 BIOS setup
SIMATIC Panel PC 877
17-56
Operating instructions, Release 07/2006, A5E00877780-01
"PCI Devices" field
If the PCI devices field is selected, the following submenu appears:
Figure 17-13 PCI devices submenu, slot #1
[Enabled] The ROM option of the PCI module (if present) is
enabled
ROM scan option:
[Disabled] The ROM option of a PCI module is disabled.
[Enabled] This slot can be assigned PCI master functions Enable master
[Disabled] This slot can only operate as PCI slave
[Default] The number of active PCI clock cycles of the
master modules is determined by this module
[0020H to
00E0H]
These settings are used to set the maximum
number of active PCI clock cycles to the selected
value
Latency timer
You should only use a value different from the default if the module
or its application requires it.