TIM-EC allows linearization or approximation of the sensor's characteristic curve using Gauss's method of least squares as described above. Linearization permits input of a sensor's characteristic curve with up to 11 data points. The set point and actual values in Nm can be determined, for example, through on-site calibration in the test bench using a lever arm dead weight machine or through stationary measurement with a reference torque transducer. Furthermore, the calibration results from a calibration, for example, in compliance with the DIN51309 or VDI/VDE 2646 standards and the resulting functional equation for linearization of the characteristic curve reading y = f(x), can be directly transferred from the calibration certificate to the Web interface.
With a large number of calibration points, this reduces both potential data transfer errorsand the time needed for input to a minimum. Transfer of the torquetransducer's serial number ensures a clear correlation between the torque transducer in use and its calibration. When the torque transducer is replaced, the serial number is automatically polled and compared to the stored entry valid for the calibration. If the serial number and thus the stored characteristic curve of the connected torque transducer does not match the stored serial number, the currently stored characteristic curve is automatically deactivated and a warning message is generated.
This message is clearly visualized in the connected Web server via the traffic light function (See Fig. 3). In addition, an error flag on the EtherCAT is sent to the control or automation system for further analysis.