How many serial ports are available and what are their device nodes?

How many serial ports are available and what are their device nodes?

The device supports up to four serial ports:
COM1: RS-232/RS-485 (Software selectable), node is /dev/ttyS4.
COM2: RS-485, node is /dev/ttyS5.
COM3 & COM4: Available via expansion modules, nodes are /dev/ttyS6 and /dev/ttyS8 respectively.