Kvaser PCIcan Hardware Reference Manual
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Kvaser AB, Mölndal, Sweden — www.kvaser.com
On PCIcan-SWC2 and
–SWC1 the CAN bus drivers are of AU5790c type
. The bus driver
requires an external power source.
The CAN bus is galvanically isolated from the card by means of fast optocouplers. These
optocouplers introduce a small signal delay and decreases the maximum allowed bus length
somewhat.
For PCIcan-S, PCIcan-D, and PCIcan-Q, the optocouplers allow for a CAN bus speed up to 1
Mbit/s.
5.3 Selecting Driver Ground (PCIcan-Q only)
Using switch pack SW1 you can connect the grounds at the driver part to the ground of the
PC. This is normally not necessary but it may sometimes be advantageous.
Switch pack SW1 is the small switch pack located near the 25-pin DSUB connector.
Table 1.
Switch Pack 1.
SW3
Function
1
ON: PC ground and the ground of CAN driver #1 and #2 are
connected.
OFF: PC ground and the ground of CAN driver #1 and #2 are
not
connected.
Default is OFF.
2
ON: PC ground and the ground of CAN driver #3 and #4 are
connected.
OFF: PC ground and the ground of CAN driver #3 and #4 are
not
connected.
Default is OFF.
3
Not used. Default is OFF.
Factory settings are: all switches OFF, meaning that the PC, and the CAN controller circuits,
are galvanically isolated from the CAN bus.
5.4 The Common CAN Bus (PCIcan-Q only)
Using switch pack SW2, you can connect the four different CAN buses to one single bus on
the board. This common CAN bus is also accessible at the DSUB connector. This allows
communication between two or more of the circuits on the card without having to connect any
cables.
Switch pack SW2 is the large switch pack near the 25-pin DSUB connector.
Table 2.
Switch Pack 2.
SW2-
When set to ON, it connects...
1
On-board terminating resistance to common CAN-L.
2
On-board terminating resistance to common CAN-H.
3
CAN-L of SJA1000 #1 to common CAN-L.
4
CAN-H of SJA1000 #1 to common CAN-H.
5
CAN-L of SJA1000 #2 to common CAN-L.
6
CAN-H of SJA1000 #2 to common CAN-H.
