For those on the Vrf this problem has been dealt with directly with Bill Gryba and the solution is given here for your information.

The programming manual shipped with the EPM441  Power Meter is a scpi programming manual.  However there is one section in the manual which refers to the HP437 compatibility language.  This section does not spell out in detail the syntax for the HP437 compatibility mode, it just list the commands. It refers you to the actual HP437 manual for the correct usage and syntax.  The problem here was in trying to mix these languages in trying to send scpi commands via direct I/O while the meter was is HP437 compatibility mode.  

Using the HP437 component driver when the meter is in HP437 mode works perfectly well.  As does direct I/O with HP437 commands.

The meter will also work  with the scpi commands, listed in the programming manual supplied with the meter, in direct I/O when the meter is in scpi mode
.
In addition there is a EPM441 VXI plug & play driver for Win95 and NT available from the following Web page

ftp://fcext3.external.hp.com/dist/mxd/vxipnp/index.html

This response has been posted with the agreement of Bill Gryba.

While the Vrf is not an official method for getting help I would be interested in any stories, good or bad, with reference to the EPM441 or EPM442 power meters.  It is only by listening to customers and their feedback that enables us (HP) to help solve your problems and improve our products.  

Adam Kohler 
Quality Assurance
Queensferry Microwave Division   
Hewlett-Packard Ltd
Scotland

-----Original Message-----
From:	gryba@SEDSystems.ca [SMTP:gryba@SEDSystems.ca]
Sent:	Thursday, October 01, 1998 7:25 PM
To:	hpvxd_xc@hpislsup.lvld.hp.com
Subject:	vrf  - epm-441a with vee

Hi
	I am using an HP EPM 441A with Vee 5.0. The power 
meter is set to hp 437 language mode (not scpi).  The power 
meter will hang up frequently when vee is taking a 
reading. I have seen this happen when using direct IO 
objects but am not sure if it also happens when using the 
437 component driver.  Has anyone else experienced problems 
with this?  This happens on two vee test setups with two 
different 441a power meters.  I am using the 437 driver 
since the 441 driver was not yet available.
Thanks

----------------------
Bill Gryba
18 Innovation Blvd.
P.O. Box 1464
Saskatoon, Sk. S7K 3P7
Canada
Ph:(306) 931-3425
Fax: (306) 933-1486
email: gryba@sedsystems.ca