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LVRefNum *VISAResourceName in DLL

Hello,
 
I'm busy with a new project where i want to communicate with a labview DLL. The DLL is a device driver with a specified interface. My first test was with a yokogawa WT230 where i tried to receive the voltage. I declared everything as a constant and the function only returned a pointer to float value (voltage). This works quite nice and i want to expand the function. The DLL declares my new function as: void YWT_GetVoltage(LVRefNum *VISAResourceName, float *MeasureValue)
 
Just like previous example I will look at the MeasureValue which is my result. However labview requires that i provide the DLL with LVRefNum *VISAResourceName and i don't understand how to send this to the dll. In the previous test I Hardcoded this in the VI as: GPIB0::1::INSTR
 
Im using Delphi and I've tried to send a pchar (pointer to character), Cardinal (unsigned 32-bit) and pCardinal (i've tried to do more things but same result) in an attempt to test this myself. I've read through the forums but i haven't been able to figure this one out.
 
Could someone please explain to me what/how to access the DLL with the LVRefNum *VISAResourceName. What type of value does this function expect from me?
 
With kind regards,
 
Erik Zwollo
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It seems that it's impossible to externally control the Visa Resource Name. I wonder if there are any other options to somehow tell the VI that it needs to connect to Device 1 on GPIB0?
 
With kind regards,
 
Erik
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Dear Gentlemen,

Somehow i managed (so it seems) to solve my issue.

First I deleted the "VISAResourceName input"  and changed it into a "string input" and was able to connect it to the VISAResourceName input of the "VISA WRITE" (complicated sentence i know).

I then updated my DLL and tried to send the string "GPIB0::1::INSTR" to the DLL and it worked.

If anyone would like more information please let me know.

With kind regards,

Erik  

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