iSMA-B-MAC36NL User Manual
Version 1.4
www.gc5.pl
Page 13 / 51
When the switch is in the END position it connects
the termination resistor 120 Ω
and biasing
resistors 680
Ω (pull
-down to ground SG and pull-up to +5VDC) to the RS485 bus.
So instead of using additional resistors, the termination and biasing can be easily done by
simple switch activation.
Figure 8. RS485 network termination and biasing