Microsoft UNO-3074 4 RS-232/422/485 Selection, 5 RS-485 Auto Flow/RS-422 Master/Slave Selection

2.3.4 RS-232/422/485 Selection

COM3 and COM4 support 9-wire RS-232, RS-422 and RS-485 interfaces. The system detects RS-422 or RS-485 signals automatically in RS-422/ 485 mode.

To select between RS-422/485 and RS-232 for COM3, adjust JP4. To select between RS-422/485 and RS-232 for COM4, adjust JP5.

You can refer to figures below to set the JP4 and JP5.

Note: Please refer to Appendix A.2 Figure A.3 for location of JP4 and JP5 location

Jumper setting for RS-422/485 interface: (Default setting).

Figure 2.2: RS-422/485 Jumper Setting

Jumper setting for RS-232 interface:

Figure 2.3: RS-232 Jumper Setting

2.3.5RS-485 Auto Flow/RS-422 Master/Slave Selection

You can set the “Auto Flow Control” mode of RS-485 or “Master/Slave” mode of RS-422 by using the SW2 DIP switch for each RS-422/485 port. (Refer to Figure A.3 for location of SW2).

In RS-485, if the switch is set to “Auto”, the driver automatically senses the direction of the data flow and switches the direction of transmission. Then no handshaking is necessary. In RS-422, if DIP switch is set to “On”, the driver is always enabled, and always in high or low status.

UNO-3074 User Manual 14