Elecom UC-SGT MacOS Configuration

The Elecom UC-SGT is one of several USB-to-serial adaptor cables based on the Prolific PL-2303 chip currently available in the market. While Prolific have implemented drivers for several common operating systems, a number of manfacturers including Elecom have chosen not to include the MacOS version of the driver with their products based on this chip. As of this writing, it also appears that the driver is no longer directly available on the Prolific technical support website.

Fortunately, several other manufacturers do distribute the MacOS driver and make it available for download. If you are fortunate, you can simply install their driver and use it with your particular manufacturers adapter. However, it is most likely you will have to make a small change to one configuration file in order to get the driver to recognize your adaptor's USB vendor and product id.

You can identify the product ID number directly using the System Profiler utility found under Applications/Utilities/. As the System Profiler displays the vendor ID as a string rather you will have to map that string to its corresponding number using a resource such as this list of USB ID'S

That in hand, the next step is to add a new (or edit an existing) stanza to /System/Library/Extensions/ProlificUsbSerial.kext/Contents/Info.plist that should end up looking something like this:

               <key>056E_5004</key>
               <dict>
                        <key>CFBundleIdentifier</key>
                        <string>com.prolific.driver.PL2303</string>
                        <key>IOClass</key>
                        <string>com_prolific_driver_PL2303</string>
                        <key>IOProviderClass</key>
                        <string>IOUSBInterface</string>
                        <key>bConfigurationValue</key>
                        <integer>1</integer>
                        <key>bInterfaceNumber</key>
                        <integer>0</integer>
                        <key>idProduct</key>
                        <integer>20484</integer>
                        <key>idVendor</key>
                        <integer>1390</integer>
                </dict>

		Where:
                    056E is your vendor ID in base 16
                    1390 is your vendor ID in base 10
                    5004 is your product ID in base 16
                    20484 is your product ID in base 10

One final warning: be careful that you have a recent version of the driver. Some releases are known to have problems with certain versions of MacOS. 1.6 under MacOS 10.3.x, for example, exhibited a problem where data could be read but not transmitted. A more recent version, 1.8, corrected this problem.

For further information and pointers to possible download sites for the driver, please consult this discussion on www.osxhax.com.