I have seen, in years past, a really good explanation as to how linx hijacks the port and the additional protocol layer that it uses (beyond TIA-232) but I have not been able to locate it. I was just looking for a little insight into the nuts and bolts of the linx DF-1 driver
I believe you can get a copy of the DF-1 protocol off of the A-B website. Other than that, when the RsLinx comm driver starts, it "opens" the port under the windows OS, which locks it from being accessed by any other programs. Pretty much standard procedure.
I know since most laptops do not come with comm ports anymore, its been an issue with ab and what 3rd party comm port device you use and how it interacts with RSLinx.
My best experience that works:
The best 3rd party devices that convert from usb to comm are the ones that install directly into the Hardware device manager. If the Device manager sees it as a serial comm port then RsLinx will see it as a comm port. Otherwise the two shall never meet or might work like maybe 50-90% of the time.
On closer reading I think that the OP is really refering to DH-485. In particular the PIC-485 adapter that goes from a serial port to the DH-485 network. I don't think that you will find any info on that.
