ASA livestream converter

Interface Converter


From 01/10/2011 (Brake Tester Directive 2011), all new brake testers delivered in Germany must have a standardized data interface, the ASA livestream interface. The determined brake forces (and other measurement data) are made available to the test engineer via this data interface (RJ45, Ethernet) as part of the main inspection of passenger cars and trucks. The ASA livestream interface is mandatory for the main inspection.

The aim of this development was to cover all existing products of our customers (plate and roller brake testers) with one version of the ASA livestream converter without having to make any changes to the electronics/software of the device.


For our customers, we developed an easy to use and compact plug & play solution to extend the existing product line.

An interface converter translates data from one interface to another, in this case an RS-485 interface (brake tester data bus) to an Ethernet interface (ASA livestream protocol).

In doing so, the interface converter performs three tasks:

  1. It converts the plug connection so that the device/bus connections with their plugs and sockets fit on both sides
  2. It provides the electrical connection for both interfaces, “input” and “output”
  3. It converts the data from one protocol to another

The technical solution is based on a Linux mini-computer (Raspberry Pi) with a newly developed HAT board. The HAT board is equipped with a UPS for safe shutdown of the computer, several status LEDs for the status indicators, ribbon cable connection for a control panel and two data bus connections (RS-232 and RS-485). The converter is connected to the brake tester via a plug-compatible data cable. An external 5V power supply is used to power the converter.