Calling dll of Leetro MPC08 PCI motion controller card problems.

[rose_lee]

Hi,

I have been trying to develop an application using Labview 8.5.  I need to control a motorized linear stage which uses the Leetro MPC08 PCI motion controller card.  The manufacturer gave me example VIs which I configure to call "c:\windows\system32\MPC08.dll".  About four months ago, I remembered that i tested them and they seemed to work somehow (but I did not finish the full test since i was busy doing other things).  Nevertheless, when I got back to continue my development a few days ago, i just could not get the same old VIs to work.  I could only get one library function of the card to work which is the "auto_set" which returns "4" which is the number of axes that the card can control.  The next function I need to call is "init_board" but this one keeps returning "-3".  The manual indicates that any negative number returned means there has been something wrong.  I would guess it is "PCI initialization fails" but honestly do not know for sure.  Can anyone help?  My computer is a PC running windows XP. 

Thanks in advance for any kind help offered.

[Mark_Ramsdale]

Hi,

Here are some general issues.

Make sure the DLL is still in location. 

Make sure you call the VI's in an order that works for the board.

Make sure the library nodes are pointing to the dll location.

Are you calling the VI's individually or in a top level VI, passing the reference (if there is one).

Can you send VISA calls directly to test the board to test functionality. ( some dll's are wrapped VISA calls).

Can you run a vendor program to verify functionality.

Hard to know without the VI's.

[rose_lee]

Dear Mark,

Thanks for your suggestions.  I will try them and post more info including the VIs and some additional info on Wednesday. 

Lastly, thanks again and youhave a great weekend.

Cheers

[rose_lee]

Dear Mark,

Here are some info I can give you now just in case you can help:

1.  The path to the DLL is definitely correct and the dll is definitely at the specified/configured location.

2.  I am quite sure that I called the VI in the order as instructed by the vendor's manual.

3.  The VIs were called individually.

4.  I have not tried the VISA called directly yet.  I will try it on Wednesday when i get to my office.

5.  I can control the motorized stage with the controller card by the vendor's program so I guess its functionality is verified.

BTW, what does the term "wrapped visa calls" mean?

Thanks.

[Mark_Ramsdale]

Hi,

Wrapped VISA call means that the SubVI contains a set of VISA calls.

If you are calling the VI's individually it is possible that the VI's need to pass a reference to each other, so they might not work if run individually.  Hard to know without the DLL docs, so to speak.  It could be possible that there is no need to pass references between subVI's.

Direct VISA calls are probably not necessary if the device runs with the vendors software.  The main goal was to verify functionality with either VISA or vendor app.

***

Ok I was looking at the Leetro web site, you can forget the VISA stuff as it is a PCI card, duh... you said that at the begining. 🙂

***

The manual says Win2000 or XP.  is this being run on two different systems?

Mark

[rose_lee]

Dear Mark,

I am running only Win XP. 

Cheers,

Rose

[Frank_L.]

Hi Rose,

Can you think of anything else that might have changed between the DLL calls working and not working? You might want to try reinstalling the device driver to see if that reconnects some dependencies that might have changed in the meantime.

Also, you mentioned that you are able to control the system using the manufacturer's example program. Are you able to see the block diagram for this code? If you can, you might try comparing their Call Library Function Node settings with yours.