Getting no where with USB-to-Serial adapters

T

transco

Member
So far I've purchased two different brands of USB-to-Serial adapters which work great in the Mac world (Intel iMac V4.6), but not in an XP VM. One problem is that they are very slow. They will work with small data bursts, but cannot sustain data flow at even 9600 baud. At this speed, they drop more characters than they pass. My guess it is either a flow control (handshake) problem, or the transfer buffers are just to small. No problem in the Mac world since both have been tested to 115.2 Kb.

My second problem is being able to consistantly bind the USB-to-Serial adapters to the VM. Seemingly at random the VM will say it can't bind them because they are being used by another process. I assume this means that OSX has assigned them to some process, but I can't find out what that is. I've looked at the processes running and don't see anything that would use the these adapters. I'm relatively new to the Mac world and might be missing something obvious. Sure could use some help running this problem down.

Finally, a question about drivers. Should both the OSX and XP drivers be installed, or just one of them. I'm not sure at what level hardware resouces are bound.

I've written over a dozen Emails to Parallels support, gotten back a dozen robot responses saying they'd get back to me in 3 days, but haven't heard from them in 60 days. I was going to try to use virtual serial ports using Unix or TCP sockets, but I'm afraid this is beyond my skill set.

I must take nightly sleep studies using a pulse-oximeter and use this information to adjust oxygen flow, medication, etc. Unfortunately the only software available for this instrument is for the Windows platform and the only hardware interface is a serial port. Sure could use some help... please!
 
I am having similar issues with USB to those that you have described.
And seems to be random in some cases (message indicating that another process is using the port)... And other times I get the message consistantly....

In addition, I ran into another strange problem, when trying to use a Flash Memory disk.
Sometimes it would bind, and other times, it would not be able to recognize the hardware.
But on those times when it did recognize the drive and mount correctly... I had a very strange problem when I tried to eject/un-mount the flash drive from Windows.

It would un-mount from Windows, but it was still mounted in OSX!
So I dragged the flash drive to the OSX trash and it then told me that the drive was in use by another application...

This is a very repeatable experience, once I finally get the Flash Drive mounted.

Harley
 
Else where in this forum there is a link to a client app that works with the VM's virtural serial ports. I tried that as well. I figured it would get around the problems we've been having. Once again, zero luck. Everything looked right, but zeo bytes were transferred into the VM app. I then tried it the other way with a serial printer on the Mac side. Once again everything looked right and it connected. Unfortunately, no data came down the pipe from the VM app to the serial port. Just for the heck of it, I tried both serial adapters at the same time figuring I could save time. Bad mistake. I had my first fatal crash since buying my Mac. The screen when dark and a message appeared in half a dozen language. I can't remember the exact wording, but it was something equivalent to "you're screwed". It wiped out the VM, the XP installation that was running under the VM and I'm still assessing the damage done to the Mac side. Bottom line, the fix has got to come from Parallels. I tried the latest beta release of the VM that was supposed to fix these serial port issues. As far as I can tell, nothing's changed.
 
If you are willing to spend around 170 bucks, you could use what I use at work every day. An Ethernet to Serial adapter.

I use the NPort Express DE311 that I purchased here:
http://www.bb-elec.com/product_family.asp?FamilyId=96&TrailType=Sub&Trail=1
or you could try a smaller/cheaper one like:
http://www.bb-elec.com/product_family.asp?FamilyId=240&TrailType=Sub&Trail=1

I used the DE311 with Virtual PC for years and now with Parallels - no problems. USB to Serial adapters have always given me fits. I know it seems like a real pain to pay more than twice as much for a serial port than for Parallels but at least it works. I really hope they get these USB problems fixed but I'm not holding my breath - Virtual PC never got it right either for whatever reason...
 
I use an AirLink 101 USB to Serial adapter and it works fine in both OS X and a Parallels W2K3 VM session. I did install the driver in OS X and then connected it through USB to the VM and installed the XP driver there. Shows up as COM3 and works like a champ.

mark
 
I have a Rocket Port 8, an 8 port Ethernet-to-Serial adapter by Comtrol, but have been unable to find a XP driver for it. For some reason they stopped supporting it with Win 2000. I'd sure lilke to get that working. I hate to spend the money for something I already have, but will check out the NPort Express. Thanks for the input.
 
Another comment... I mentioned earlier that I haven't had any luck with SerialClient. I put a line analyzer on it and discovered it never raises DTR. Apparently this accounts for some of the problems I've been seeing.
 
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The NPort DE311 has always handled the hardware flow control lines (DTR,RTS,CTS) like a champ. It really looks and acts like a "true" serial port to XP. If you try one make sure to get the latest firmware upgrades and com port mapping drivers from their web site. I remember having trouble in Windows XP until I did this. (newly purchased ones should all be up to date by now I would guess)
 
mark_julmar said:
I use an AirLink 101 USB to Serial adapter and it works fine in both OS X and a Parallels W2K3 VM session. I did install the driver in OS X and then connected it through USB to the VM and installed the XP driver there. Shows up as COM3 and works like a champ.

mark
Click to expand...

Mark,

I see the Airlink adapter product information at their website, but I do not see drivers for OS X - did it come with drivers?

Thanks...
 
I am having the same problems.

So far I have tried a new FTDI cable (to go with my new iMac ) with drivers installed in XP + MacOS, MacOS only and XP only. The Mac finds the device OK but get the the, dreaded, message 'USB device you are trying to connect to the virtual machine is being used....etc.

So I reverted back to my trusty Keyspan which has worked for years on my iBook with virtualPC.

Gues what exactly the same problem. And again I have tried all the combinations of drivers installed.

Unfortunately I need to use windows applications for a amateur radio log book seral connections.

I can't believe that this is an isolated problem.

For everything else I have tried Parallels is a excelent improvement over virtual PC. Mind you the blistering speed of the Mac does help.:)
 
Since posting the above I have been looking around some more (using Keyspan as search) and found a thread - 'Keyspan usb serial adapter not working'. And low and behold the following:-

If you have a USB serial adapter (I have a Keyspan), you can try this:
http://eudyptes.com/SerialClient.php

Thanks to Eudyptes for a great tool to make Parallels talk to serial devices!

I endorse this - good patch worked first time with my USA-28.

Mind you I did not know that you had to add a serial port manually - must have missed that somewhare.
 
Can't see serial port in Mac OS X

Hi! Saw the 'solution' for the serial port issue from macmike6 who linked to (http://eudyptes.com/SerialClient.php) for the answer. (Parallels socket connection to Mac IO device)
The only problem I have is that the serial port does not show up in the Serial Client program (or Mac System profiler for that matter - except as a USB device).
I have installed the Mac drivers for OS X from Silicon Labs (the adapter is a CP2101 USB to UART Bridge Controller). But I do not see a serial port listed in the profiler on the Mac. The only ports showing up in the Serial Client are the bluetooth ports. The drivers for CP2101 are found here http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/USB/en/mcu_vcp.htm

Any suggestions?

Thanks
Todd
 
Any more news on this issue since this last post? I have a keyspan single port usb 2 serial adapter - and I can't get it working with XP and parallels on an imac core 2 duo. I URGENTLY need it working, either in a "virtual" mode or a direct XP/USB mode. - as long as it works - right now I can not get either working! In virtual PC it was easy I just installed the drivers for the keyspan, then routed the keyspan to com1 in the VPC preferences and it worked like a charm. I'd really appreciate any help on this at the moment.

Miklos.
 
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