I am new to LabWindows/CVI, so please forgive my ignorance, but I've been struggling for several days with the very basics of creating an IVI Specific Driver, using the IVI Instrument Driver Wizard tool, and getting nowhere.
I am trying to create the most simple Serial IVI driver I can, to see if I can get some communication flow from a test app created with CVI on a PC to a new device, which is a SocKit evaluation board with an SoC and some on-board I/O interfaces. The new instrument has a serial port and an Ethernet port... ultimately I'd like a driver that can connect to either.
I'm using the IVI Instrument Driver Wizard to create the serial driver.... using CVI 13.0.
When I get to the 'Test' page of the Driver Wizard, it asks for a Resource Descriptor, and provides the default of "ASRL1::INSTR".
My question is where am I supposed to get this descriptor?
My device is connected to COM4 (which is a USB Serial Port with an FTDI driver installed to convert USB to serial...). I know that communication on this port from the PC to the device works, because I can set up a putty terminal connection and connect to a linux 'sh' program running on the board.
Currently I just want to test this driver to see if the device sees any 'receive' data on its serial port ... so I've told the driver that I want it to send an Identification Query as part of the Initialization.
If I keep the default Resource Descriptor of ASRL1::INSTR, and select 'Run Tests...', I'm fairly sure that no communication is going across COM4... I dont' see any Rx LEDs light up on the device. But the tests act like they're trying to communicate with something, and eventually return with the following:
Serial Port Configuration
...Passed
VISA Initialization
Return Code : 0x0 (VI_SUCCESS: No error)
ID Query
Return Code : 0xBFFF0015 (VI_ERROR_TMO: A timeout occurred)
I've change the Resource Descriptor to "ASRL4::INSTR", and also tried "COM4", to see if I can see any Rx LEDs light up on the device... but in any of these cases, when I click 'Run Tests...', CVI immediately returns with an error message...
Could not get the board number for the given interface. (VI_ERROR_INV_RSRC_NAME: Invalid resource reference).
So one problem is that I don't know where I'm supposed to get a valid Resource Descriptor to try communicating across the PC's COM4 port ??
I've also tried building and installing this driver, and running NI MAX.
Within NI MAX, the new driver shows up under IVI Drivers->Advanced->Instrument Driver Software Modules.
But it does not show up anywhere else (e.g. under "Devices and Interfaces", or "IVI Drivers->Driver Sessions"). I don't know if this is something I need to fix first before expecting to provide a valid Resource Descriptor, or really what to try next.
Just to be clear, I don't have any communication software specifically set up to run on the device... but it has a built-in Serial communication capability, and as mentioned above, this has been tested by connecting to an embedded linux 'sh' app running on the device, using putty on the PC.
I'm hoping I can verify that I have a mechanism for communicating through an IVI driver to the device, before putting an IVI/Visa compatible app on the device that provides the desired communication interface.