29 UTC-520 User ManualChapter 4 Jumper Settings and Connectors4.2 Jumpers4.2.1 Jumper list4.2.2 Jumper SettingsTable 4.2: Jumper ListJ2 COM2 SettingJ3 AT / ATX Power SELJ4 Clear CMOSJ5 Panel Voltage SELTable 4.3: J2: COM2 SettingPart Number 1653003260Footprint HD_3x2P_79Description PIN HEADER 3*2P 180D(M) 2.0mm SMD SOUARE PINSetting Function(1-2) RS232(3-4) RS485(5-6) RS422Table 4.4: J3: AT / ATX Power SELPart Number 1653002101Footprint HD_2x1P_79_DDescription PIN HEADER 2*1P 180D(M)SQUARE 2.0mm DIP W/O PbSetting Function(1-2) AT Power SELEMPTY ATX Power