DAWN: Data Acquisition With In-Vehicle Networks
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Use a Scan Tool for Data Acquisition?
DAWN text
Rick Walter Scan tools are designed for service technicians to diagnose problems. A major benefit of scan tools is that they go beyond the Legislated OBD-II (Test Mode $01) parameters by supporting Enhanced Diagnostics. Thus, they provide many hundreds of parameters from a variety of controllers.

Most data acquisition systems that interface to the vehicle’s network are limited to acquiring the 96 OBD-II emission related parameters.

Since scan tools have many parameters beyond just OBD, are readily available and are generally inexpensive, the logical question is, “Why shouldn’t I just use a scan tool for data acquisition?”

Scan tools do have many benefits, but they also have limited display and storage capabilities. They usually have a 20 Hz aggregate sample rate and typically acquire data from only one controller at a time, which is a reasonable limitation for a service tool but not for a data acquisition tool.

HEM Data has created a product that combines the flexibility of a scan tool with the display and storage capabilities of a data acquisition system. DAWN (Data Acquisition With Networks) is the solution. It offers:

  • The ability to acquire both OBD and Enhanced Diagnostics, along with a wide range of flexibility to display the data. DAWN also acquires parameters at high sample rates – up to controllers’ maximum rate of 250 samples/sec.
  • Support for a wide variety of Test Modes, or Service IDs. Legislated OBD-II only defines hexadecimal modes $01 to $10. DAWN supports the Enhanced Diagnostic modes greater than $10, offering flexibility in the types of acquired data – including high speed parameters, diagnostic trouble codes, VIN, and clearing trouble codes.
  • Simultaneous acquisition of various types of data from multiple controllers, including diagnostic, trouble & pending codes. This allows the user to see all of the acquired data before and after a trouble code has tripped.
  • Configuration to detect user-defined conditions, extending the OBD and OEM-specific codes to detect codes earlier or monitor for conditions not covered by the standard codes.

So, while a scan tool may not offer the solution you’re looking for, DAWN can fill in the gaps and provide superior data acquisition performance.

To learn more about the flexibility of DAWN, click here.

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