Data communication interfaces, Figure 24 – Vaisala WMT52 User Manual
Page 48
User’s Guide ______________________________________________________________________
46 ___________________________________________________________________M210925EN-B
Data Communication Interfaces
0505-206
Figure 24
Data Communication Interfaces
With RS-485 and RS-422 interfaces, termination resistors need to be
used at both ends of the line, if data rate is 9600 Bd or higher and
distance is 600 m (2000 ft) or longer. Resistor range 100 ... 180
Ω
is
suitable for twisted pair lines. Resistors are connected across RX- to
RX+ and across TX- to TX+ (with two-wire RS-485 only one resistor
needed).