I see a lot of people that have issues with USB <-> Serial adapters. I just figured I would share with everyone else what I use and maybe others can chime in here.
I purchased one of S2 Squared's S2USB485 adapters while I was working for a company that will remain nameless but pretty much owns the N2 protocol. I could not get the edgeport adapter I had previously to work with the laptop I had at the time or the CVTPRO I had either. The S2 adapter worked great for connecting to any N2 device I needed to.
But one of the side benefits is the serial adapter on the thing is bulletproof. I have been able to connect to every single piece of equipment I've ever tried with and with multiple laptops and desktops. I've used it on DX's, Liebert intellislots, Turborcor compressors, serial shell into Jace's, Alerton BCM's, Alerton Apex's APS UPS's, and a ton of other random equipment RS-232 ports that I've had absolutely no business getting my unqualified hacking fingers into. I would suggest to anyone in the controls or equipment field to grab one. Between that adapter and the B&B USBOPTL4 (I think that's what it's called) I can get into just about anything I've come across in my market.
I just wanted to throw that out there. I see quite a few guys on here that seem to have problems with their usb to serial adapters and I figured that I would share and give the adapter a thumbs up. Hope this is not an inappropriate post, but helps some people out.