TS-78000 COM Ports Info ======================================================================= There are 1, 2 or 3 COM ports on the DB9 connector. RTS and CTS can be software switched into another TXD/RXD pair. DTR and DCD can be software switched into another TXD/RXD pair. This is 3 total with RS-232 transceivers. The COM 2 header has an single RS-232 port and two optional RS-485 ports. This is a total of 4 RS-232 ports with RS-232 transceivers. The COM3 header can be 1 or 2 COM ports. RTS and CTS can be software switched into another TXD/RXD pair. This is 6 total RS-232 ports with RS-232 transceivers. There are 2 more COM ports that can be switched onto the DIO header. These two ports do not have RS-232 transceivers. They have TTL levels. Each of these ports has a TXD/RXD pair and a TX Enable signal useful for implementing RS-485 transceivers. There are 2 more COM ports that can be switched onto the 40-pin PC/104 bus connector. These two ports do not have RS-232 transceivers. They have TTL levels. Each of these ports has a TXD/RXD pair and a TX Enable signal useful for implementing RS-485 transceivers. This makes a total of 10 COM ports (serial ports). 6 have RS-232 levels and 4 have TTL levels. Plus there are optionally 2 more RS-485 ports which can be configured as a single RS-422 port (= full-duplex RS-485).