Hi. I hope this is the right place to ask. I have downloaded the "POS for ..NET SDK" from the microsoft web site, and I'm trying to use it to control my various OPOS devices.
My first device was the "Line Display" and it worked fine. Then I added more devices, and the printer and cash drawer work, but the msr does not, and the line display stopped working too.
Now for both the msr and the line display, when I call open(), it fails with the error "Closed". I don't understand this. Of course it's closed, that's why I'm opening it. For both of these devices, the opos test applications that came from the manufacturer work fine.
I get the devices from POSExplorer. But even without POSExplorer, it's not any better. In the case of the line display, if I try to open the device using the logical device name, I get the same error. In the case of the msr, it does not have a logical device name. In fact, I tried 2 msrs from Magtek and ID Innovations, and neither has a logical device name, so for the msr, I can only try the device that comes back from POSExplorer.
Can anyone help me with this? Why would an open() return the error "Closed" ?