The RSB Serial Booster was designed to drive up to 20 E3C compliant optoisolated NCD devices from a single RS-232 serial port with a DB9 connector.
The RSB has been tested to drive RS-232 signals at 1000+ feet at data rates up to 38.4K baud. Simply plug it into your RS-232 port, provide +12 volts to power the board, and run the In, Out, and Ground lines to all devices on the network. Use the E3C command set to control which device you want to speak to.
NCD devices use an open-collector (O.C.) system for communicating data back to the computer. O.C. RS-232 signals allow several devices to share 3 data communication wires, but are NOT compatible with standard RS-232 signals.
The RSB serial booster is used to convert these O.C. signals back into PC compatible RS-232 levels. Note that this device cannot be used to send data from NCD devices back to a Macintosh computer, but has been tested to be fully compatible with all PCs.