Hi,
guess you should provide more details on the error you get.
-Are you using any instrument driver for that instrument?
-What is the subVI that throws the error?
Also you may want to attach a screenshot of the error so that people can look at what's going on.
Here you can find the instrument driver for your instrument:
http://search.ni.com/query.html?lk=1&col=alldocs&nh=500&rf=3&ql=&pw=595&qp=%2BContentType%3AInstrumentDriver+%2BIDNetInstrumentType%3A%22Power+Supplies%22+%2BIDNetManufacturer%3A%22Hewlett-Packard%22+%2BProductType%3A%22LabVIEW%22&qt=&layout=IDNet
Regards,
AlessioD
National Instruments