The comments from the others are excellent, and worth pursuing. I also checked Agilent's web site. In <a href="http://we.home.agilent.com/cgi-bin/bvpub/agilent/library/cp_LibraryFAQDetail.jsp?OID=536977078&NAV_ID=-536886896.536883195.03&LANGUAGE_CODE=eng&COUNTRY_CODE=ZZ";>this article</a>, they made it sound like the 4142B is very similar to the 4155/4156 series.
NI has a driver for the 4155/4156 series <a href="http://zone.ni.com/idnet97.nsf/9b2b33e1993d877786256436006ec498/8b48a562db255488862568ab005fb9a2?OpenDocument";>here</a>. You might want to try using that driver as a starting point; it might be easier than starting from scratch. I hope this helps. Post back here to let us know if this worked for you. (And if you create your own driver, consider submitting it back to <a href="http://ni.com/idnet/";>ni.com/idnet</a>.) Brian
