2.3.7 Termination Resistor (JP6)
The onboard termination resistor (120 ohm) for COM3/COM4 can be used for long distance transmission or device matching (Default Open).
| | RS-422 | RS-485 |
COM3 | Close A | TX3-TR | Data+, Data- |
| Close B | RX3-TR | |
COM4 | Close C | TX4-TR | Data+, Data- |
| Close D | TX4-TR | |
Close: Enable termination resistor.
Note: Please refer to Figure A.3 for location of JP6
2.4 LAN: Ethernet Connector
The UNO-3074 is equipped with a Realtek RTL8139C Ethernet LAN con- troller that is fully compliant with IEEE 802.3u 10/100Base-T CSMA/CD standards. The Ethernet port provides a standard RJ-45 jack on board, and LED indicators on the front side to show its Link (Green LED) and Active (Yellow LED) status.
2.5 Onboard Isolated Digital Input
The UNO-3074 has 4 isolated DI channels designated DI0~DI3.
2.5.1 Pin Assignments
The connector type of UNO-3074 is plug-in screw terminal block that enables you to connect to field I/O devices directly without additional accessories. Figure 2.4 and Table 2.4 shows its pin assignment as well as signal description.
Figure 2.4: Digital Input Connector Pin Assignments