Communicating wirelessly with CAN networks
For several years, some vendors have provided CAN gateways with wireless links, especially those with Bluetooth applications. Therefore, devices connecting CAN and wireless networks have become standard for CiA members and technicians. The CiA 812 application note describes use cases for CiA 457 compliant gateways. The CiA 457 CANopen gateway profile specifies the wireless communication links. This includes configuration parameters and diagnostic as well status information. The profile supports Bluetooth, WLAN, and proprietary solutions. In typical applications single or multiple sensors are connected wireless to the CANopen network or remote radio I/O modules control the mobile machinery (e.g. crane and other construction machines). Those user panels are equipped with joysticks, pushbuttons, and other I/O elements. If the wireless connected modules are CANopen devices, a tunneling of CAN messages interpreted as CANopen protocols as specified in CiA 315 is reportedly possible. "Since August, CiA has released internally the CiA 315, CiA 457, and CiA 812 documents, which allow a flexible usage of wireless communication links in a CANopen system," said Holger Zeltwanger, CiA Managing Director. "Especially in mobile machines this will simplify system design of heterogeneous network architectures." The system integrator also should refer to the CiA 302-7 bridge-/router specification, in which the Remote SDO and Remote EMCY protocols are defined.
CAN in Automation
– Edited by Chris Vavra, Control Engineering, www.controleng.com