AnsweredAssumed Answered

vrf Calling Sherlock Holmes

Question asked by VRFuser on Aug 20, 2004
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML><HEAD><META http-equiv=Content-Type content="text/html; charset=us-ascii"><META content="MSHTML 6.00.2800.1458" name=GENERATOR></HEAD><BODY><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2>Not sure what I just read.  A properly designed UL HiPot test will not discharge into a grounded circuit.  Anyway, the ground current is isolated from the rest of the circuit (should be, and no current should be on ground), hence, assuming slow rise time, everything moves with respect to ground.  So, with this, I think you might have some grounding problems.  You might want to check your circuit isolation, suggest you use a low voltage DMM to start.  Also, ground should be ground everywhere.  So if you isolated ground, how does everything get back to ground ref.  I know, I know, each return should return to the same point at each box, and each box returns to the point somewhere at distribution.  So I'd be concerned with what you mean, when you say, you've isolated the hipot ground. Note, I know your box circuits can use chassis as return, but this is only a ref and does not complete a circuit path.  Think of the secondary of the transformer as everything in a box.  Pick one point at chassis and tie this to that box.  Hence, no closed circuit, therefore no current.  This should be true everywhere.  Now that I have you completely confused,  don't forget ground loops.  Well we won't go there, these will only affect fast rise times and almost any frequency.  So ...  Just don't forget that you hi-pot has to ref ground at the device under test, then how is this ground isolated?</FONT></SPAN></DIV><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2>The second issue can be almost anything, but suggest something is not properly set at start-up, could be an external device, or internal variable.  I would have to look at the code.  But what I'm hearing, I dunno.  Try putting a breakpoint within your code, say halfway through to see if the error still occurs.  Use a kinda binary sort for placement of the breakpoint until you are able to turn it on and off between two adjacent objects.  Then fix the one that's broke.  Note, you should be able to locate the spot, if it exist, within Log2(#Objects)</FONT></SPAN></DIV><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV><DIV dir=ltr align=left><SPAN class=319104819-20082004><FONT face=Arial color=#0000ff size=2>Rufus</FONT></SPAN></DIV><BR><DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><HR tabIndex=-1><FONT face=Tahoma size=2><B>From:</B> Robert A Marquardt [mailto:ramarquardt@ra.rockwell.com] <BR><B>Sent:</B> Friday, August 20, 2004 10:24 AM<BR><B>To:</B> VRF<BR><B>Subject:</B> [vrf] vrf: Calling Sherlock Holmes<BR></FONT><BR></DIV><DIV></DIV><BR><FONT face=sans-serif size=2>Hello all,</FONT> <BR><BR><FONT face=sans-serif size=2>These should go into Ripley's Believe It Or Not !</FONT> <BR><BR><FONT face=sans-serif size=2>Problem #1</FONT> <BR><FONT face=sans-serif size=2>VXE library files get corrupted during test runs.</FONT> <BR><FONT face=sans-serif size=2>Observed with VEE 6.01 on both Win NT and Win 2000.</FONT> <BR><FONT face=sans-serif size=2>Also, we were using VEE Development with the VXE files.</FONT> <BR><FONT face=sans-serif size=2>Occured when HiPot tester inadvertantly injected a ground current into the test</FONT> <BR><FONT face=sans-serif size=2>equipments ground plane. The Low Voltage side of the HV touched ground</FONT> <BR><FONT face=sans-serif size=2>during a fixture self test where an intentional fault existed.</FONT> <BR><FONT face=sans-serif size=2>Also occured on a functional tester where someone was using a GFI as an ON/OFF</FONT> <BR><FONT face=sans-serif size=2>switch. When pressing the "TEST" button on the GFI it injects 120V ~3mA into the ground plane</FONT> <BR><FONT face=sans-serif size=2>and shocks the system.</FONT> <BR><BR><FONT face=sans-serif size=2>Problem #2</FONT> <BR><FONT face=sans-serif size=2>Same circumstances as Problem #1 except that the VXE files only APPEAR to be corrupted.</FONT> <BR><FONT face=sans-serif size=2>This happened with both VEE RunTime and VEE Development using VXE files.</FONT> <BR><FONT face=sans-serif size=2>VEE starts up with various errors displayed, sometimes it crashes, sometimes it</FONT> <BR><FONT face=sans-serif size=2>just can't find variables which should have been initialized. This is repeatable,</FONT> <BR><FONT face=sans-serif size=2>we can even reload all the VXE files and it still occurs.</FONT> <BR><FONT face=sans-serif size=2>Upon reboot, everything is Hunky Dory.</FONT> <BR><BR><FONT face=sans-serif size=2>Note: The problems went away after the HiPot return lines were isolated from equipment ground</FONT> <BR><FONT face=sans-serif size=2>and when the GFI was replaced with a regular switch. However, every now and then a HiPot</FONT> <BR><FONT face=sans-serif size=2>fixture gets miswired or an old fixture is redesigned and we end up repeating the problem again</FONT> <BR><FONT face=sans-serif size=2>as happened here yesterday.</FONT> <BR><BR><FONT face=sans-serif size=2>Any ideas?</FONT> <BR><FONT face=sans-serif size=2>I really would like to know whether VEE is doing the file corruption</FONT> <BR><FONT face=sans-serif size=2>and why VEE can't run properly without a reboot. I suspect that Windows</FONT> <BR><FONT face=sans-serif size=2>is messed up memory wise but this only happens with VEE. NI & DOS</FONT> <BR><FONT face=sans-serif size=2>based systems have never exibited these problems. I suspect VEE is dependent</FONT> <BR><FONT face=sans-serif size=2>upon some expected pre-existing condition of the O.S. when starting - is</FONT> <BR><FONT face=sans-serif size=2>there some way to detect and correct it before startup?</FONT> <BR><FONT face=sans-serif size=2>Regarding the file corruption, is VEE leaving the file handles open after</FONT> <BR><FONT face=sans-serif size=2>loading the librariesand maybe Windows just goes berserk when the</FONT> <BR><FONT face=sans-serif size=2>ground faults occur?</FONT> <BR><BR><FONT face=sans-serif size=2>Maybe I could this to P.T. Barnum for the entertainment of VEE users worldwide?</FONT> <BR><BR><FONT face=sans-serif size=2>Stumped</FONT> <BR><FONT face=sans-serif size=2>....Rob<BR><BR>Rob Marquardt<BR>Rockwell Automation / Allen-Bradley<BR>1201 So. 2nd St. / T131<BR>Milwaukee, WI. 53204-2496<BR>USA<BR><BR>ramarquardt@ra.rockwell.com<BR>414-382-3098<BR>414-382-4820 (FAX)<BR><BR><BR></FONT>--- You are currently subscribed to vrf as: rwarren@amti.net To subscribe send a blank email to "join-vrf@it.lists.it.agilent.com". To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com". To send messages to this mailing list, email "vrf@agilent.com". If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".---<BR>You are currently subscribed to vrf as: rsb@soco.agilent.com<BR>To subscribe send a blank email to "join-vrf@it.lists.it.agilent.com".<BR>To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".<BR>To send messages to this mailing list,  email "vrf@agilent.com".  <BR>If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".</BODY></HTML>  

Outcomes