Screw terminal serial connectors, Figure 3-4. screw terminal ports – Lantronix 900-422 User Manual
Page 19
3: Installation and Hardware
XPress DR+ User Guide
19
Screw Terminal Serial Connectors
Table 3-2. Serial Screw Terminal Pinout for RS422 (4-Wire)
Pin Direction Name
Function
1
Output
TX+
Transmit Data +
2
Output
TX-
Transmit Data -
3 Ground GND Signal
Ground
4
Input
RX+
Received Data +
5
Input
RX-
Received Data -
Table 3-3. Serial Screw Terminal Pinout for RS485 (2-Wire)
Pin Direction
Name
Function
1
Bi-directional
TX+/RX+
Transmit Data + and Received Data +
2
Bi-directional
TX-/RX-
Transmit Data – and Received Data -
3 Ground
GND
Signal
Ground
4
Not Applicable Not Applicable Not Used
5
Not Applicable Not Applicable Not Used
Figure 3-4. Screw Terminal Ports
Note:
Termination resistors (R = 120 Ohm) are used to match impedance of a
node to the impedance of the transmission (TX) line. Termination resistors
should be placed only at the extreme ends of the data line, and no more than two
terminations should be placed in any single segment of an RS-485 network. The
terminator resistors may not be needed for your application.