RS232 Comms port in MacPro

Discussion in 'Mac Pro' started by chris172, Oct 15, 2012.

  1. chris172 macrumors newbie

    Oct 15, 2012
    First post... :D

    Have been a lurker on here for quite a while and have found it very resourceful. I now need some advice that I can't find an answer to.

    Got a MacPro 4.1 Quad 2.93 and have Windows install via Parallels with XP Professional for pc stuff.

    Looking to get a computerised matt board cutter that is Windows PC ONLY and communicates via RS232.

    Question... there are Pci cards out there that say they are Mac friendly but does anyone know if they are recognised by a Windows volume running on a Mac?

    I have searched but not found anything about RS232 and a PC partition. Don't particularly want to buy a PC

    Thanks in advance

  2. ActionableMango macrumors G3


    Sep 21, 2010
    I use the Keyspan USA19-HS in OS X, Windows through Boot Camp, and Windows through Parallels.

    It is USB, not a card.
  3. fuzzypickle macrumors newbie

    Sep 3, 2012
    Insofar as I know, if you're running windows on it's own partition, you basically are running a PC. The bootcamp stuff enables all the nifty apple-specific goodies that're built in, but if you can find drivers for something in windows, it'll work regardless of whether the hardware came from apple or not (it just may not work on the osx side).

    I'm sure there's someone here who can attest to this more accurately than I though.

    As an alternative, what about a USB-serial adapter cable?
  4. goMac macrumors 603

    Apr 15, 2004
    Another vote for the USB adapter. They work particularly well and are a lot more VM friendly.
  5. chris172 thread starter macrumors newbie

    Oct 15, 2012
    Thanks for the replies so far....

    I have been told by the manufacturer that USB converters do not work that well with these machines... not sure why. They need a dedicated RS232 Comms port.
  6. Mikey7c8 macrumors regular

    Sep 15, 2009
    Montreal, Canada
    That's really unfortunate, as the serial adapter is the way to go normally - have seen them used with success for routers/switches and etc.

    Could always try and see I guess
  7. ytk macrumors regular

    Jul 8, 2010
    That's ridiculous. RS232 is a standardized protocol. You're either in spec or you're not. As long as their hardware is fully RS232-compliant, you should be able to use any adapter that also meets the specification.
  8. ActionableMango macrumors G3


    Sep 21, 2010
    There are timing or conversion issues with many cheap USB to RS232 adapters that can affect sensitive devices. I know in my case (programming a HAM radio) the Keyspan unit works where other USB-to-serial adapters are known to not work.

    I picked the Keyspan USA-19HS specifically because it is widely regarded to work with most devices. It is also a driverless installation on Windows, OS X, and off-the-shelf Linux.

    Obviously I cannot promise anything, but I'd try the Keyspan out from a retailer that has a fair return policy.

    Not ridiculous at all. You provide the very reason why so many cheap adapters don't work... "You're either in spec or you're not." They are cheap junk made at rock bottom prices that very loosely or unreliably fits the spec and causes problems with unforgiving devices.
  9. saulinpa macrumors 6502a

    Jun 15, 2008
    Some really old crappy Windows software came with special drivers that talked to the hardware directly. I remember one for process control where you had to tell it the I/O address and IRQ of the COM port in a config file. Mostly stuff that was originally DOS based.
  10. ColdCase macrumors 68030

    Feb 10, 2008
    Belkin also makes decent USB-Serial adapters. You probably need one that accommodates flow control, which most low cost USB-Serial adapters don't bother with. IRQs are just the way you used to have to set up DOS.
  11. ytk macrumors regular

    Jul 8, 2010
    Well, then your adapter doesn't meet the specification now, does it? :D

    My point is that, as long as the adapter is of a decent enough quality that it speaks proper RS232, the device on the other end has no way of knowing whether the adapter connects to the computer via USB, PCIe, or even smoke signals for that matter. There's nothing inherently wrong with a USB adapter that would cause it not to work properly.
  12. hfg, Oct 15, 2012
    Last edited: Oct 15, 2012

    hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    My guess would be that the software provided with the serial driven device expects to communicate directly with the hardware registers in the serial UART, and doesn't do as well with the hardware emulators that drive the USB-RS232 converter cables.

    If you are planning on booting directly to Windows to run this application, I would think any Windows PCIe RS-232 card would work just fine. In this mode, your Mac is a standard Windows machine. The "BootCamp" stuff is really just the board level hardware drivers the same as would come with any motherboard.

  13. deppest macrumors member

    Oct 6, 2009
    I second the keyspan USB adapter. I have been using one on different MacPro's from 1,1 to 4,1, mainly to connect GARMIN GPS and PSION devices. Used it on both OSX and windows side, sometimes required a bit of fiddling with the setup but overall did its job.

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