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StarTech.com 2 Port USB to RS232 RS422 RS485 Serial Adapter with COM Retention ICUSB2324852
This single adapter is compatible with any serial device protocol RS232 RS422 and RS485 and even allows mixing protocols for simultaneous communication over both ports
COM retention saves the assigned port settings for the device so disconnectingreconnecting is hassle-free
USB Powered - no power outlet required and no cumbersome AC adapter to carry around
Backwards compatible with USB 11
USB-powered No additional external power adapter required
Both ports can function simultaneously with mixed or matched communication protocols