Black Box Multipoint Line Driver LD485A-MP Standalone - short-haul modem -

Extend async RS-232 data beyond the 50 ft limitation over CATx at data rates up to 64 kbps and reach distances up to 4 miles in point to point or multipoint environments. This RS-232/RS-485 Multipoint Line Driver is basically an interface converter that operates like a short-haul modem, enabling your data to travel across much longer distances than is normally possible. Its big advantage is running multipoint and point-to-point applications. In fact, you can daisychain and run up to 64 devices with a single controller at speeds of up to 64 kbps! You can also attach non-RTS equipment. With Driver Enable Selection, the driver senses incoming data and connects the host automatically.