User manual

9 UNO-1110 User Manual
Chapter 2 Installation
2.4 Serial Connections
2.4.1 Serial Mode and Terminator Resistor Selection
UNO-1110 provides 5 serial Com ports, COM1 - COM4 provide RS-232/422/485, and
COM5 provides RS-485. The default settings of COM1 - COM4 are RS-232. Users
could change COM1 - COM4 Port serial types to RS-422 or RS-485 by SW3/SW4
DIP switch selection located on rear side of the UNO-1110 system.
You can enable RS-422/485 terminator resistors if necessary to match impedance.
Especially in fields with electric noise, enabling terminal resistors is helpful to stabi-
lize communications. Make sure that both sides of the RS-422 or RS-485 communi-
cation ports are installed on BUS.
Users could change COM1 - COM4 serial port type and RS-422/485 terminator resis-
tor settings by SW3/Serial Port Setting DIP switch located on rear side of the UNO-
1110 system according to the table below.
Table 2.4: COM1 - COM4 Serial Port Setting
COM1/COM3
DIP Switch
COM2/COM4
DIP Switch
Serial Mode Receiver Termination Mode
RS-232 Standard Mode N/A
RS-485 Auto Flow Mode 120 Ohms Terminator Resistor
RS-485 Auto Flow Mode No Termination
RS-422 Master 120 Ohms Terminator Resistor
RS-422 Master No Termination