Brainboxes ES-357 Product Manual page 19

Suppose we want to connect the Brainboxes Serial Port to the serial port of another PC. Connect the
earth lines. Line 5 of Serial Port 2, to lines 1 & 7 of the other PC. This gives the two devices a
common earth level.
Connect the Transmit and Receive lines together. Line 3, TXD, Port 2 goes to line 3, RXD, of the
other PC. Line 2, RXD, Port 2 goes to line 2, TXD, of the other PC. This allows each to receive the
data transmitted by the other.
Connect the Port 2 DTR line, pin 4 to the other PC DCD, pin 8 and CTS, pin 5, lines. Also, connect up
the other PC DTR line, pin 20 to the Port 2 DCD, pin 1 and CTS, pin 8, lines.
This allows the receiving device to signal when it can no longer accept data. The receiving device
sets DTR false when it is unable to receive any more data. The sending device reads DTR on its CTS
and DCD pins. It should stop sending when CTS goes false.
Connect the Port 2 RTS line, pin 7, to the other PC DSR line, pin 6. Also, connect the other PC RTS
line, pin 4, to the Port 2 DSR line, pin 6. This RTS line is used to let the other device know that it is
ready for data exchange.
Version 2.9
ES Range Product Manual Page 19 of 66
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