CPCI Backplane
General
ID 24229, Rev. 03
© 2005 Kontron Modular Computers GmbH
Page 11
2422
9.03.UG.VC.051007/14565
3
P R E L I M I N A R Y
3.7
Connector Coding Keys
Figure 6:
Backplane/Rack Coding
Keys
Kontron Modular Computers
Compact-
PCI systems present an advantage in
the form of a special combination of
coding keys. They ensure proper mating
of boards and backplanes in terms of
voltage and function. For this purpose,
two different kinds of coding keys have
been devised, which are described in
the following.
Backplane Keying
Proper board installation is ensured by
the use of colored coding keys for 3.3V
(yellow) or 5V (blue) operation, thus pre-
venting incorrect installation of adapter
boards. This facility also prevents confu-
sion when hot-swapping boards.
Additional Backplane Keying
The function of the additional board cod-
ing key depends on the backplane.
Backplanes equipped with an H110 tele-
phony connector are marked with a red
H110 key. Dual-PCI backplanes use
coding keys for 3.3V (yellow) or 5V
(blue) operation of the upper PCI bus.
Rack Keying
Boards must be fitted into a CompactP-
CI backplane in a certain order, depend-
ing on whether they are bus master
boards or I/O boards. To this end, spe-
cial asymmetrically shaped coding keys
can be used by the customer to ensure
that the boards are inserted properly.
Main Board Coding Key
Rack Coding Keys
Yellow: 3.3 V (NCR)
Blue: 5.0 V
Red
Additional Board Coding Key
Red: H110 present
No key
P4
P1
PCI Connectors
Yellow: 3.3 V (NCR)
Blue: 5.0 V
P1 and P4
