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Data acquisition

Recording and analyzing analog vehicle data

CAS Data Logger offers the Adwin-Gold systems, which converts analog data to CAN data frames. This enables to analyze them in conjunction with the information available on CAN-based in-vehicle networks.

The data logging devices are available in different versions with dedicated analog input capabilities (Source: CAS Data Logger)

In road, off-highway, and off-road vehicle engineering projects it is sometimes useful to convert analog data and combine it with data in the CAN-based in-vehicle networks. There are a few basic steps to convert sensor data from analog to CAN data frames:

  • Read the analog output of the sensor at the desired sample rate.
  • Perform any required signal processing such as filtering or averaging and scaling the output to the desired engineering units such as temperature, pressure, etc.
  • Convert the value from engineering units to hexadecimal numbers with any required formatting such as offset or scale factor.
  • Encode the hexadecimal value in a CAN data frame with the specified CAN-ID and the appropriate offset.
  • Either broadcast the data frame or load it into a register in the case of a remotely requested data frame.
The shown sample program is for an ADwin-Pro system with a Pro-Ain-32/16 16-bit analog input card and a Pro-CAN-2 two-channel CAN interface card. (Source: CAS Data Logger)

The Adwin-Gold systems are available in several models with different analog input capabilities. They are all suitable for this application when outfitted with the CAN interface option. The flexibility of the programming environment makes it easy to read and scale the data. High-level functions and built-in message structures allow the generation and transmission of CAN data frames. This is shown in the example below.

The Adwin operating system is event-based, which allows periodic data frame generation without the need for special timing routines. In the sample program, the global-delay statement configures the event-loop to read the sensor and send the data every millisecond. In this example, the data is being broadcast. In the case of remotely requested data frames, the CAN interface can be configured to look for a particular CAN-ID and generate an interrupt to trigger the event-loop and send the desired data.

Other features of the systems include built-in high-level functions and the ability to program calculations. In the example below, a single instruction can be used to return the input voltage. Mathematical functions allow scaling calculations to be done with a single, intuitive equation. These capabilities enable more complex operations such as averaging, filtering and statistical operations. Internal routines, which handle casting operations, make it possible to manipulate integer, floating point, and binary data transparently.

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Publish date
2019-07-30
Company

Jaeger Messtechnik
CAS Data Logger

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