Background information: RS422 and RS485 interfaces are differential interfaces of low impedance and thus indifferent to interfering signals. The ports are therefore particularly suitable for use in industrial environments where data is to be transmitted over long distances. The two devices must however be properly isolated from each other. Voltage between devices can result in incorrect data transmission or the destruction of the interfaces.
Technical data:
Number of ports:
2 isolated RS422/RS485 ports
Operating modes:
RS422 RS485 2/4 wire with handshake control RS485 2/4 wire with automatic control
Switching time:
approx. 10µs for switching from data send to receive for RS485 automatic control (can be changed on request)
UART:
16550 with FIFO
Base addresses:
03F8H, 02F8H, 03E8H, 02E8H
Interrupts:
IRQ 3..7, IRQ 9..12
Data format:
any format
Baud rate:
50..115,200 baud
Signals:
RxD A/B, TxD A/B, CTS A/B, DTR A/B
Serial connections:
9-pin SUB-D connector
Galvanic isolation:
Isolation voltage min. 1 KV DC between PC and serial ports
