Operating As An Rs-485 Interface; Figure 11: Rs-485 Bus Termination - WAGO I/O SYSTEM 750 Manual

WAGO-I/O-SYSTEM 750
750-8208 PFC200 CS 2ETH RS CAN DPM
3.3.6.2

Operating as an RS-485 Interface

To minimize reflection at the end of the line, the RS-485 line must be terminated
at both ends by a cable termination. If required, one pull-up or pull-down resistor
may be used. These resistors ensure a defined level on the bus when no subscriber
is active, i.e., when all subscribers are in "Tri-state".
Attention — bus termination!
The RS-485 bus segment must be terminated at both ends!
No more than two terminations per bus segment may be used!
Terminations may not be used in stub and branch lines!
Operation without proper termination of the RS-485 network may result in
transmission errors.

Figure 11: RS-485 Bus Termination

Manual
Version 1.1.0, valid from FW Version 02.06.20(09)
Device Description 37