CAN in Automation (CiA) has released the CiA 446 specification. It describes the standardized CANopen/AS-Interface gateway. The gateway provides NMT slave functionality on the CANopen side; NMT master functionality may be implemented additionally. On the AS-Interface side up to two AS-Interface masters may be connected per logical device. Theoretically, up to eight logical devices may be implemented in a single CANopen device. The gateway specification supports M0 to M4 AS-Interface master functions.
In the document 132 Transmit-PDOs and 132 Receive-PDOs are described to communicate digital and analog input/output signals from the two AS-Interface sub-systems. All AS-Interface parameters may be configured by means of SDO write services to the CANopen object dictionary of the gateway. By means of SDO read services it is possible to get the status of any AS-Interface slave device.
"In the past, the communication with CANopen sub-layered AS-Interface systems was manufacturer-specific," said CiA's Olga Fischer, who is responsible for this gateway specification. "The standardized CiA 446 CANopen interface profile at least a partial re-use of application software in the programmable CANopen control system, if gateway devices are interchanged." The companies Bihl & Wiedemann, ifm electronic, and Schneider Electric participated actively in the standardization of the CiA 446 interface profile.