VME-CAN-AE252 ESD Electronics Intelligent CAN Interface Board

The ESD Electronics VME-CAN2 / VME-CAN2B Series 2 Interfaces to CAN or DeviceNet Modules are an intelligent interface equipped with 2 independent CAN channels and with an additional serial port for programming and service purposes. The board includes all necessary components on a VMEbus 6U board and needs only one slot.

The VME-CAN2 contains a local MC 68000 CPU at 20 MHz clock frequency and 512 kB shared SRAM as well as a bidirectional 4 kwords FIFO interface for the processing of complex CAN data transfer protocols.

The BASIC CAN Controller 82C200 is used normally as the controller component. The integrated firmware enables operation as a full CAN controller. The version VMECAN2B used the controller 82527. It works as a master for standard (11-bits identifier) or for extended- (29-bits identifier) CAN protocol.

The physical CAN layer is according to ISO 11898 for a maximum baudrate of 1 Mbit/s. The CAN channels are electrically isolated from each other as well as from the VMEbus section. The local power supply is performed by DC to DC converters.

The extremely error tolerant CAN protocol (Hamming distance = 6) is excellently suited for the construction of decentralized I/O networks, where a safe and manufacturer independent communication protocol is necessary because of the variety of applications.

The advantages of the CAN protocol mainly result from the transfer frame standardized in the automobile industry, from the high transfer rate of up to 1 Mbit/s and from the error tolerance for extremely disturbed environment. Additionally the CAN protocol is self-arbitrating and has multimaster capability, which enables the user to interconnect in a single CAN network various sensors, actuators, CAN I/O modules or process controllers (esd-Xbus, VMEbus).

The VME-CAN2 is suitable for communication with other VMEbus systems or esdXbus controller systems (e.g. esd-XCAN) or PC's, as well as for operation of a fast decentralized I/O network with CAN I/O modules. The standardized higher layer protocol CAL/CMS is available as a master or slave package for nearly all operating systems.