DVPSCM12-SL has two RS-485/RS-422 ports (COM1 and COM2). Full isolation between the RS-485/RS-422 communication and the power supply.Two built-in 120Ω terminal resistors are driven by external switches. Every port can be connected to 32 devices at most. MODBUS ADVANCE: easy software setting interface for MODBUS data exchange. UD Link: user-defined communication protocol and procedure planning.