Jtdrv is the Java version of the Tdrv test program. See Testing with Tdrv in the LayGO Installation Guide for details on Jtdrv's features and operation.
To start Jtdrv, at the command prompt enter:
java advancedrelay.jtdrv.Jtdrv stack6.cfg x21loop.cfg
See the Help → Using Jtdrv... dialog for more information on Jtdrv's command line options.