ASAM ASAP 3 defines an RS232 communication protocol between a test automation system and a measurement & calibration system connected to an ECU. The TCP/IP protocol can be used as an alternative, although not directly supported by the standard. The standard describes obsolete technology and has been replaced by ASAM MCD-3 MC in the meantime. ASAM continues to publish ASAP 3 to support existing legacy systems that are still in use. If given the choice, ASAM recommends to use ASAM MCD-3 MC.