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Abstract. Most modern off-road machinery use embedded electronic controllers connected to a controller area network (CAN) to broadcast machine information for on-board processes and diagnostics. Commercially available tools can record CAN data for a variety of research and commercial uses. For agricultural tractors, there is an opportunity to create advanced test procedures that are more representative of field operations and that could supplement existing machine performance tests, such as the OECD Code 2 Standard Code for the Official Testing of Agricultural and Forestry Tractor Performance. CAN parameters provide an efficient way to collect tractor performance data during field operations. However, the accuracy of CAN messages is not known, and little information was found in the literature regarding the accuracy of CAN messages or validation of reported signals. The objective of this study was to investigate the accuracy of net engine torque as calculated from several relevant CAN channels by comparing it to torque measured with a calibrated laboratory dynamometer. Results of this study indicate statistically significant differences between calculated and measured net engine torque, although there was a strong correlation. Recommendations for future work include replicating this study on more and different engines that report actual engine percent torque - fractional (SPN 4154) and estimated engine parasitic losses - percent torque (SPN 2978). This would provide higher-resolution torque estimates that may help explain the torque differences observed in this study. Keywords: Accuracy, Agricultural machinery, Calibration, Controller area network, CAN bus, Data acquisition, Diesel engine, Dynamometer, Equipment performance, J1939, Machinery, Off-road vehicles, Power take-off, PTO, Tractors, Torque.

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HighlightsA novel data acquisition system was developed to synchronously log CANbus machine operating parameters with auxiliary sensor data converted and transmitted via the ISObus.A relationship between the number of added messages and frequency of transmission was evaluated.Knowledge of existing bus loads can lead to successful deployment of the data acquisition system for field data logging of both machine and implement data.Abstract. While standalone CAN data loggers offer a simplified, plug-and-play solution for agricultural machinery performance data collection, information that can be obtained from these devices are limited to data contained within interpretable messages broadcast over the machinery CAN bus. For machinery performance parameters that cannot be interpreted from CAN data, alternative methods are needed to record these variables. This application note discusses the development of a customized solution, named the Sensor CAN Gateway (or SCANGate), that integrates various components, including an Electronic Controller Unit (ECU), to allow auxiliary sensor data to be recorded by a CAN data logger through message transmission over a tractor’s ISOBUS. Testing with a modern tractor validated that the impact on bus load from added messages transmitted by the SCANGate could be determined based on the number of additional messages added per time interval. With knowledge of existing bus load requirements for an implement connected to a tractor’s ISOBUS, it can be determined whether the SCANGate can further enhance a standalone CAN data logger for a given application. Keywords: Agricultural machinery, CAN bus, Controller Area Network (CAN), Data acquisition, SAE J1939.