Serial Port - Ballbar 2

[Phil747]

I first want to thank Dennis Knutson for his answer to my previous question about the ballbar and serial communication. I'm now able to communicate with it using MAX. But when I try to use the Labview "Basic_Serial_Write_and_Read" VI, I instantly get an error saying "Error -1073807246 occurred at Property Node (arg 1) in VISA Configure Serial Port (Instr).vi->Basic_Serial_Write_and_Read.vi". It also tells me that my resource is valid, but than VISA can't access it. I am wondering which argument is arg 1 and aslo what can be creating this error. Thanks a lot.

Philippe

[Dennis_Knutson]

Glad I could help. When you get the error, do you have any other program open that is accessing the serial port (i.e. hperterminal). Windows doesn't allow different programs access to the same port.

[Dan_Mondrik]

Philippe:

In this case it isn't really about arg1 at all. The resource you passed into the Configure VI (presumably something like COM1 or ASRL1::INSTR) is busy - the error is VI_ERROR_RSRC_BUSY. This means that you most likely have some other application using the resource, like Hyperterminal.

For what it's worth, the property node refers to each property in order, so the first property inside the Configure VI is the timeout. This is the first point at which that VI needs to use the resource you passed in, so that's when it tries to open the VISA session and fails. So it failed when trying to do a 'set' on arg1 because in this case it couldn't open the resource.

Dan Mondrik
National Instruments

[rolfk]

Phil747 wrote:

> I first want to thank Dennis Knutson for his answer to my previous
> question about the ballbar and serial communication. I'm now able to
> communicate with it using MAX. But when I try to use the Labview
> "Basic_Serial_Write_and_Read" VI, I instantly get an error saying
> "Error -1073807246 occurred at Property Node (arg 1) in VISA Configure
> Serial Port (Instr).vi->Basic_Serial_Write_and_Read.vi". It also tells
> me that my resource is valid, but than VISA can't access it. I am
> wondering which argument is arg 1 and aslo what can be creating this
> error. Thanks a lot.

Did you close the commmunication window in MAX? Maybe just close MAX
altogether. Serial ports can usually only be accessed by one application
and MAX is also an application.


Rolf Kalbermatter