COM

Serial Port Specifications

COM1 & COM2 support RS232/RS485 protocols; COM3 & COM4 support RS232 protocol. Serial ports operate exclusively on the real-time control layer without virtualization support.

COM1/COM2 Interface Definition (RS232/RS485 Dual-Mode)

COM1/COM2 Pinout
Pin assignments for combo RS232/RS485 ports

Pin	Signal Name	Pin	Signal Name
1	COM1_DCD# / RS485-	6	COM1_DSR#
2	COM1_RXD / RS485+	7	COM1_RTS#
3	COM1_TXD	8	COM1_CTS#
4	COM1_DTR#	9	N/C (Reserved)
5	GND

COM3/COM4 Interface Definition (RS232)

Pin	Signal Name	Pin	Signal Name
1	Not Connected	6	Not Connected
2	RXD	7	Not Connected
3	TXD	8	Not Connected
4	Not Connected	9	Not Connected
5	GND

Protocol Implementation Notes

Dual-Mode Signaling: COM1/COM2 pins 1/2 serve dual roles:
⚡ Standard RS232 signals (DCD#, RXD)
⚡ RS485 differential pairs (RS485-/RS485+)
Hardware Selectable: Protocol mode determined by DIP switch or BIOS setting
Industrial Isolation: 2.5kV optical isolation on all serial ports (IEC 61000-4-5)

Last modified: 2025-06-16