CANpro/104 User Manual
15 www.connecttech.com CTIM-00043 (0.01) 1/15/2010
800-426-8979 | 519-836-1291
Single Interrupt Mode
This mode routes the interrupt signal from both SJA1000 CAN controllers to one PC/104 Bus
Interrupt signal. This mode is set up by installing Jumper J1/J2 Position “S” (either the CAN-0 or
the CAN-1 “S” position can be used). When this jumper is installed, the Interrupt signal occurs on
the “CAN-0 row” of J1 and J2 (red box).
Dual Interrupt Mode
This mode routes the interrupt signal from the CAN-0 SJA1000 CAN controller to the CAN-0
PC/104 Bus Interrupt signal and the CAN-1 SJA1000 CAN controller to the CAN-1 PC/104 Bus
Interrupt signal. This mode is set up by removing Jumper J1/J2 Position “S”.
J1/J2 Position “S”
Function
Removed
Dual Interrupt Mode
Installed
Single Interrupt Mode
Table 15
Shared Interrupt Mode
In either the Single or Dual interrupt modes, the PC/104 Bus Interrupt Signal can be shared with a
similarly selected interrupt on another PC/104 board (which supports shared interrupts). There are 2
jumpers which control this sharing on J3C Positions #3 and #4.
J3C Position
Function
Jumper Installed
Jumper Removed
3
CAN-1 Interrupt Shared
CAN-1 Interrupt Not Shared
4
CAN-0 Interrupt Shared
CAN-0 Interrupt Not Shared
Table 16
Shared Interrupt Pull-Down
When shared interrupts are employed, there MUST be one board (among the boards that share the
same interrupt) that MUST be setup to activate a Pull-Down resistor on the Interrupt signal. This is
accomplished by Jumper J3C Position #5.
J3C Position #5
Function
Removed
Shared Interrupt(s) Pull-Down disabled
Installed
Shared Interrupt(s) Pull-Down enabled
Table 17
Interrupt Selection
In either of the CAN-0 or CAN-1 groups there is 11 possible interrupts that can be selected. The
jumpers are numbered by the PC/104 Bus Interrupt number (3, 4, 5, 6, 7, 9, 10, 11, 12, 14 or 15).
Only one jumper should be installed in the appropriate group.
CAN Bus Dominant Timeout and Minimum Speed
The CANpro/104 board implements a CAN Bus transceiver which has a “Dominant State timeout
feature”. This feature prevents the board from permanently holding the CAN bus in the “Dominant
state”. Due to this feature, the minimum CAN Bus data rate supported is 20K bps.