
Kvaser PCIcanx II User's Guide 9(18)
Kvaser AB, Mölndal, Sweden —www.kvaser.com
3.3 The Isolated CAN Drivers
Each CAN transceiver is isolated from the CAN controller and all other CAN transceivers. The
CAN transceiver will get the necessary power from the PCI bus via an isolated DC/DC
convert. The isolation between the CAN controller and the CAN transceiver has a delay of
maximum 50 ns in each direction. This will reduce the possible cable length with 20 meter
compared to having no isolation.
Due to human safety, the voltage should never at any part of the PCIcanx II board be more
than +/- 50 Volt from the PC-computer chassis ground. If any USB pin has an external voltage
in the range below +/-500 Volt from chassis ground this will also be the true voltage at this
pin.
Each CAN transceiver circuit is protected from short time over voltage like ESD and
accidental short cuts to high voltage. An over voltage beyond +/-500 Volt, on any used DSUB
pin, will cause a rapid shortcut to ground. If the applied over voltage do have a high-energy
source some PCB wires may burn away in that case.
3.4 PCI-X and PCI slots
The universal design of the Kvaser PCIcanx II boards makes them suitable for both PCI-X
and PCI slots. Although the board fits in PCI-X as well as PCI slots, it is not a PCI-X product.
Hence, it operates in PCI mode in all slots. Major features of the Kvaser PCIcanx II board:
Compliant with PCI Local Bus Specification v2.3
Support for PCI-X Specification v 1.0 and higher versions
Universal 3.3V and 5V keyed board connector
Supports 3.3V and 5V supply voltage
Operates at a bus frequency of 33MHz
To summarize, the Kvaser PCIcanx II boards can be used in any PCI-X and PCI slots. Just keep in
mind - all cards on a common bus can only run as fast as the slowest card. For example if there is
a 33MHz card in slot 1 and a 66MHz card in slot 2, both cards will run at 33MHz. The performance
degradation can be avoided by separating the Kvaser PCIcanx II board (33 MHz/32-Bit) and other
PCI and PCI-X devices using different bus segments. Note –not all motherboard vendors comply
with the industry standards for PCI-X and PCI slots. Kvaser AB cannot assume any responsibility
for that. Here is a list of supported PCI-X and PCI slots:
3.3V, 64 bit
3.3V, 32 bit
5V, 64 bit
5V, 32 bit.
The PCI connectors voltage keying is seen in Figure 3.
Figure 3. The PCI connectors voltage keying