The device becomes a different COM ports on different computers (e.g. COM6, COM11).

Well-known behaviour of most USB-to-RS232 adapters with Windows. It depends on the available internal COM ports (based on 8250 / 16450 / 16550 and clones), the virtual COM ports that once were used (e.g. by other USB-to-RS232 adapters or Bluetooth devices), and sometimes even on the actual USB port into which you plug the adapter. Someone at Microsoft must have decided that it is a good idea to reserve COM ports for devices that had been plugged in ages ago.

This particular imported no-name USB->RS-232 device was based on the Prolific (a Taiwanese company) PL-2303 chips, as I suspect many commercially available models are. Use the install software that comes with the device - NOT a generic driver from Prolific. Make sure the device says it supports Windows 7 if that's what you're going to use it on. I installed it successfully on one XP computer using the device manufacurer's software. When I tried in on another XP computer using Prolific's generic sofware from their website - it failed miserably. Reboot after installing -even if it doesn't tell you to do so.

There seem to be two different kinds of such adapters. Some identify as a generic RS232 adapter and are supported out-of-the-box by the drivers that came with Windows. And the other ones need vendor- or chipset-specific drivers. I would try to avoid the second type, because no vendor spends much money on testing the driver software for a device that costs less than 6 €. Most vendor drivers seem to be rebranded chipset drivers from the chipset manufacturer.

Note that Linux handles USB-to-RS232-adapters a little bit different: The first free device name is assigned, typically /dev/ttyUSB0 for the first adapter, /dev/ttyUSB1 for the second one, and so on. No reserved devices. Unless you configure udev to identify a certain adapter by its vendor and device ID and its serial number and to assign it a constant device name. Other adapters will still get the first free device name.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

In reply to Re^5: Win32::SerialPort v. New computers by afoken
in thread Win32::SerialPort v. New computers by hennesse

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.