Mountain Lion compatible Serial-to-USB adaptor recommendation

Question

Can someone recommend a Serial-to-USB adaptor that is compatible with OS X Mountain Lion.
Thank you in advance,
DKG

Answer 1

VikingOSX wrote:
Here is a link to a USB to DB9 solution.
I have used that one and it works.
Here is a similar model that I still use and it works as well:
http://www.tripplite.com/en/products/model.cfm?txtSeriesID=782&txtModelID=3915
That one has two RS-422 ports.
Their drivers for Mountain Lion work perfectly, as do the earlier ones for PPC Macs. I have used it with every OS X version since Jaguar.
It does install a kernel extension but as far as I have been able to tell, it is well-behaved and I have experienced no conflicts. The .kext is not active unless the adapter is actually connected.
Follow the driver installation instructions carefully - the adapter must be disconnected while installing the driver or the installer package will crash. The package installer dialog tells you this.
Here is a summary from my notes:
Disconnect the Keyspan adapter from your Mac. If you do not disconnect the adapter, the installer package will crash.
Open the downloaded zipfile to expand the keyspanUSAdrvr installer package.
Read the "Important Information", authenticate when necessary, and complete the installation. The Keyspan driver is a kernel extension necessary for the Keyspan adapter to work.
Connect the Keyspan adapter after the installer completes.
An alert may appear indicating that "new network interfaces were detected" and need to be configured. You may ignore this alert, and you may delete the three Keyspan network interfaces that will now appear in System Preferences > Network. OS X seems to think these are dialup modem drivers. They are not used for printing. The alert will not reappear.
A logout / login or reboot should be optional to ensure the driver is loaded. If in doubt, reboot.
With the adapter connected and its driver correctly installed, the kernel extension will now appear in System Information as KeyspanUSAdriver.
In Applications, locate and open Keyspan Serial Assistant. When the adapter has been connected its serial port names will appear in this window. Clicking the reveal triangle will show their names.
KeySerial1 is an alias to the first port on the first Keyspan adapter connected to your Mac. The names USA28XxxxxP1.1 and USA28XxxxxP2.2 will change if the adapter is connected to a different USB port. Connect your serial device to Port 1 on the adapter, and use KeySerial1 for the serial port name. Otherwise it will be necessary to change the name of your serial port every time you change which USB port the Keyspan is using.
Leave Keyspan Serial Assistant in your Applications folder since you may need it to refer to these names in the future.
To uninstall the Keyspan driver software, open Keyspan Serial Assistant, select "Uninstall USB Serial Extension" from the Settings menu, and follow the instructions. Administrator authentication is required to uninstall the driver. The extension will then be eradicated from your system. The only remaining files are the Keyspan Serial Assistant application, the installer package, and the downloaded zipfile. To completely delete everything drag all these files to the Trash.
Keyspan had previously labeled their OS X 10.8 driver a "beta" version, which worked fine. They since dropped the "beta" label. Hopefully this indicates they are interested in continued support. In any event I doubt any updates would be required for future OS X versions any time soon, since it is already a 64 bit driver.