Target Requirements : Describing Different Target Platforms : Detailed View of I/O Card Description File : Trace Settings

Trace Settings

The trace settings option enables you to trace data items of basic type, conditions, events, states and activities without using the Rational Statemate debugger in a less intrusive manner.

The selection of the traced elements is done using three matrices in the Trace Settings window of the Options menu.The trace of every selected element can be turned off or on.

In addition, there is a pop-down menu that sets the format of the trace file or disables it. There are two formats of trace file:

You can supply your own function, which will be called every time that the traced element is changed. It allows creation of the trace file in the format appropriate to different tools.

The tracing text data is written to the <output directory>/<profile name>.trc file by the Remote Server that receives the messages from the TRACE_TASK via TCP/IP socket communication, which usually has lower priority than the other tasks. It reads the trace lines from the buffer, where they were put during execution between two sequential steps in the TRACE_TASK. It means that the buffer size, which the user can change, should be big enough. The buffer size is set in the Target Task Settings window.

In fact, polling rate, priority and buffer size are interconnected. If the priority is low (e.g. 255 is the lowest available priority for VxWorks), the buffer size should be as big as possible. If the polling rate is big (i.e. it is a number of ticks of the delay between two sequential steps in a task loop), the buffer size and the priority should be higher.

The run-time trace process is controlled by two conditional expressions: start trace and stop trace. The first is evaluated at the beginning of the step in model, and the second at the end of the step. The empty start trace field is equal to TRUE. The empty stop trace field is equal to FALSE. This makes the trace continuous.