The SET COUNTERS command establishes execution counters at all
    program locations specified by the node specifications. After you
    enter the GO command, the Collector counts the number of times
    each specified program location is executed and records each
    execution in the performance data file.

    If you enter the SET COUNTERS command before entering a SET
    DATAFILE command, the Collector establishes a default data file.
    The default data file has the same file name as your program's
    executable image file and a file type of PCA.

    You must collect stack PC information if you want to use a /MAIN_
    IMAGE, /CUMULATIVE or /STACK_DEPTH qualifier with the PLOT or TAB
    command in the Analyzer.