Over 485-interface slaves are connected as multi drop, physically daisy chain.
Those have built-in termination resistor, and the value is 120 ohm and no select switch for termination on/off.
So it makes termination value as 120hm if I connect 10 slaves.
If I want to make it as properly, just put 60 ohm resistor on each data Line(D+, D-)?
Master A(D+) -----(60 ohm)-----~~~
Master B(D-) -----(60 ohm)-----~~~
My guess is it can affect as like below:
60 ohm + 12 ohm(parallel connection from 10 slaves) + 60 ohm = 132 ohm
Surely, the best way is changing termination resistor, but I want to make it work simply.