CANopen Data Tunnel for MODBUS Configuration
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Solution Overview
Problem
Existing methods for configuring and parameterizing field devices with a CANopen interface are costly and time-consuming due to the inability to access and transmit data beyond the limitations of the CANopen object dictionary, particularly when devices have a MODBUS interface, requiring direct one-to-one connections for configuration.
Innovation Solution
The method encapsulates MODBUS frames within CANopen frames using a data tunnel object, allowing SDO downloads to facilitate configuration and parameterization via the CANopen bus, enabling transparent access to all data and parameters through a standardized SDO service, even for devices with different interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If direct one-to-one connections are used for configuring field devices with MODBUS interface, then configuration can be performed, but the process becomes costly and time-consuming
Solution Approach 1:
The patent introduces a gateway device as an intermediary between the configuration device and field devices. The gateway translates MODBUS communication protocols into CANopen protocol, enabling centralized configuration through the CANopen bus without requiring direct one-to-one connections. This mediator resolves the contradiction by maintaining configuration capability while eliminating the need for multiple direct connections, thereby reducing time and cost.
Solution Approach 2:
The gateway device provides universal communication capability by supporting both MODBUS and CANopen protocols. It can translate and forward communication between devices using different protocols, allowing a single configuration device to access multiple field devices through the CANopen bus regardless of their native interface type. This multi-functionality eliminates the need for separate configuration connections for each device.
2Adaptability or versatility
If data transmission is limited to CANopen object dictionary, then CANopen protocol compliance is maintained, but access to additional data and parameters is restricted
Solution Approach 1:
The patent implements a nested communication structure where MODBUS communication is encapsulated within the CANopen protocol framework. The gateway translates MODBUS PDU (Protocol Data Units) into CANopen SDO (Service Data Object) communication, allowing MODBUS data access through the CANopen bus. This nesting enables extended data access capability while maintaining outer-layer CANopen protocol compliance, as the translation occurs at the protocol boundary.
Data Source
AI summary
The invention relates to a method for transmitting data between a first automation appliance, and at least one second automation appliance, via a CANopen bus using a service data object as an SDO service, wherein an SDO client implemented in the first automation appliance is used to send a download or upload request to an SDO server implemented in the at least one second automation appliance, wherein the data are encapsulated in a CANopen frame by an application implemented in the first automation appliance or the at least one second automation appliance wherein the CANopen frame with the encapsulated data is transmitted or sent by means of an SDO service into or out of a data tunnel object defined in an object dictionary of the SDO server, and wherein the encapsulated data are decapsulated by the application implemented in the first or the at least one second automation appliance.