Chapter 3
Pin # Pin #
DB9
B16
8
B17
4
B18
9
B19
5
B20
NC
Notes: The shaded area denotes power or ground. RS232 signals are listed first followed by
RS485/RS422. The signals marked with * = Negative true logic.
42
Signal
Description
CTS4*
Clear To Send 4 – Indicates external serial communications device is
ready to receive data. Used as hardware handshake with RTS4 for low
level flow control.
RX4+
RX4+ – If in RS485 or RS422 mode, this pin is Receive Data 4 +.
DTR4* Data Terminal Ready 4 – Indicator Serial port 4 is powered, initialized,
and ready. Used as hardware handshake with DSR4 for overall
readiness to communicate.
NC
Not connected
GND
Ground
NC
Not connected
Reference Manual
Hardware
ReadyBoard 700