CAN in Automation (CiA) has released the CANopen multi-level networking specification (CiA 400) and the CANopen application profile for road construction machine-sensor systems (CiA 415)—documentation is available for CiA-members. CiA-400 specification supports the design of CANopen-based systems that use multi-level networks. It’s possible to describe systems up to 127 CANopen networks, with each network comprising up to 127 CANopen devices. The CiA-400 gateway is able to support up to 32 CANopen interfaces. It’s possible to forward service Data objects (SDO) as well as emergency messages. NMT requests and the heartbeat information are forwarded through the entire system by remote SDO. Process Data Objects (PDO) are limited to the local networks and are not forwarded. However, it is possible to map system variables into the local PDOs and handshake them to the next network level.
New standardization activities. The CANopen Special Interest Group (SIG) crane/spreader will define an interface specification based on CANopen to interconnect crane control systems to spreaders. Andy Lewis, from Sweden-based Bromma, chairs the SIG that will provide a stable work draft specification by yearend 2006. CiA expects to present first results at November’s Bauma exhibition in Shanghai.
CiA is also calling for RFID experts to develop a CANopen device profile for RFID reader devices. Several CANopen-based control systems require RFID information, for example in laboratory automation, storage systems, production lines, and such. The first RFID reader with CANopen connectivity is already on the market: RM Michaelidis has developed a device that is used with forklift applications.
— Richard Phelps , senior editor, Control Engineering
