CAN is currently the de facto standard for bus systems in the automobile industry. The fact that sales of CAN-related components have surpassed the most optimistic sales estimates is a clear indication of the relative success of the CAN bus. The CAN interface card described here is intended for installing into a free ISA expansion slot in your PC. Great for experiments in getting acquainted with CAN.When it comes to developing an application employing the CAN bus in one way or another, a PC is an indispensable ‘tool’ for debugging and testing. Assuming you want to develop 100% bug-free application (and who doesn’t?) the PC and a suitable interface card will allow you to visualise and record CAN frames travelling up and down the bus, as well as supply test frames. To show you the basics of how it’s done, we’ve developed a small test application running under Windows. This little program will not fail to demonstrate the main features of the card.At the same time, the interface described here may be the heart of a complex automation system because it is compatible with current industry standards like CANOpen and DeviceNet. We have to emphasise, however, that the present adapter card does not have any on-board intelligence, so that all processing of whatever protocol has to be handled by the PC. In certain cases, the resultant software overhead may be significant.