Intelligent CAN-ISA gateway development to industrial networks and Internet coupling

To couple the several devices in a distributed system control with other levels, it is necessary to use a gateway. In our case some development cards based in a microcontroller using a control area network (CAN) controller simulates an industrial network in the laboratory. The gateway is the PC including the CAN-ISA card and the software to control the communication system and monitoring from the LAN. As it is necessary to perform this coupling in real time, and the PC must work with other tasks, the gateway must be intelligent. This paper exposes the design criterion and the steps taken into account to get this device and the software implementation to guarantee the interconnection between the CAN and LAN. The interface card employs several hardware resources such as shared memory between microcontroller and PC, microcontroller´s memory map dynamically configurable, control handshaking by interrupt, and it has employed the Xilinx tech using a programmable CPLD to reduce the hardware. This card has been designed and built by separate modules. These are prepared to teach and to permit upgrades with new emerging technologies. There are two software modules, one for the server linked to CAN bus and other for the client linked via the LAN for remote monitoring