Purpose

Maintains a connection channel to an ECU using the VW TP 2.0. Format

Input

diag ref in specifies the diagnostic session handle, obtained from Open Diagnostic on CAN FD.vi and wired through subsequent diagnostic VIs. Normally, it is not necessary to manually manipulate the elements of this cluster.
error in is a cluster that describes error conditions occurring before the VI executes. If an error has already occurred, the VI returns the value of the error in cluster to error out.
status is TRUE if an error occurred. This VI is not executed when status is TRUE.
code is the error code number identifying an error. A value of 0 means success. A negative value means error: the VI did not execute the intended operation. A positive value means warning: the VI executed intended operation, but an informational warning is returned. For a description of the code, wire the error cluster to a LabVIEW error-handling VI, such as the Simple Error Handler.
source identifies the VI where the error occurred.

Output

diag ref out is a copy of diag ref in. You can wire it to subsequent diagnostic VIs.
error out describes error conditions. If the error in cluster indicated an error, the error out cluster contains the same information. Otherwise, error out describes the error status of this VI.
status is TRUE if an error occurred.
code is the error code number identifying an error. A value of 0 means success. A negative value means error: the VI did not execute the intended operation. A positive value means warning: the VI executed intended operation, but an informational warning is returned. For a description of the code, wire the error cluster to a LabVIEW error-handling VI, such as the Simple Error Handler.
source identifies the VI where the error occurred.

Description

For the VW TP 2.0, you must periodically maintain the connection link to the ECU so that the ECU does not terminate it.

This VI sends a Connection Test message to the ECU and evaluates its response, performing the steps necessary to maintain the connection.

There is no equivalent for the ISO TP (ISO 15765-2), as the ISO TP does not use a special communication link.