Avalue EEV-EX13 - Manual (Page 9)

Quick Installation Guide
EEV-EX13 Quick Installation Guide 9
2.3 Setting Jumpers & Connectors
2.3.1 COM1/COM2 pin 9 signal select (JP2, JP3)
*
*Default
JP2 (COM1)
Ring*
+5V
+12V
JP3 (COM2)
Ring*
+5V
+12V
2.3.2 COM2 RS-232/422/485 Select (JP4)
* Default
Note:
Replace JCOM1 by JRS422/1
when the using RS-422/485 mode.
RS-232
RS-422
RS-485