Yet another string communicaiton passing issue with DLLs

[nistdude]

I am trying to connect to a Yasakawa Motoman MOTOCom DLL using a call library function node

I can read strings generated MOTOcom functions using the C String defintion

ie short BSCIsJobName(short nCid, char*jobname, short size)

where the in the paramters

return is a numeric-16 bit signed integer

ncid is a numeric-16 bit signed integer

*jobname is a string - C String Pointer

size is a numeric-16 bit signed integer

but writing out to the same format fails

short BSCSelectJob(short nCid, char*name)

where the in the paramters

return is a numeric-16 bit signed integer

ncid is a numeric-16 bit signed integer

*name is a string - C String Pointer

common issue: i can read and write numerics and pointers to arrays of numerics but can only read strings - not send them to the DLLs

i have been playing with DSNewPtr to create a pointer and MoveBlock to set it up

and trying to send the resultant pointer to the paramenter defined as INSTANCE DATA POINTER with crashing results. never makes it to DSDisposePtr....

I have included the DLL definitions - auto import doesnt work as it just creates C String Pointers like i did manually.

please help.

[nathand]

Can you show how you're configuring the Call Library Function Node? There should be no problem getting data out of a string. Are you pre-allocating the string before you pass it to the DLL? You should make sure you initialize a string to the correct length, either by creating a string of the right length as a constant, or using "Initialize Array" to create an array of U8, then doing Byte Array to String.

[Freddy.]

I have another question, how do you establish a connection with the robotic arm using the Motoman MOTOCom DLL? When I call the BSCOPEN function, I keep returning code -8, but it works fine in debugging software and C #

[rolfk]

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@Freddy. wrote:

I have another question, how do you establish a connection with the robotic arm using the Motoman MOTOCom DLL? When I call the BSCOPEN function, I keep returning code -8, but it works fine in debugging software and C #

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My magic crystal ball still doesn’t work so I can not see the VIs you did NOT attach! And please attach the actual VIs, not an image of them and if you use a newer LabVIEW version than 2020, please do first a “Save for previous version”