user13193: I imagine that the proper way to implement an RS485 multidrop bus is the following:

What happens if, in order to save cables, I connect the same 5 nodes above using this other topology?


Will it works? 
If no, why? 
If "maybe", under which circumstances will it work?


P.S.: yes! I know that MEGA has three Serials and, as such, I could implement two different BUSses (1: Mega<->Mega<->Mega; 2: Mega<->Nano<->Nano), but this will increase the complexity of the software I'm running, as it needs some hacking in order to play nicely with two distinct RS-485 busses;
P.P.S.: This is the bus discussed in this other question

user4143: At low speeds and short distances that won't be a problem.
At high speeds (megabits per second) and long distances (hundreds of meters) you may get reflections unless you get the termination just right.

13193: <p>I imagine that the proper way to implement an RS485 multidrop bus is the following:</p>

<p><a href="https://i.stack.imgur.com/iScLl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iScLl.png" alt="enter image description here"></a></p>

<p>What happens if, in order to save cables, I connect the same 5 nodes above using this other topology?</p>

<p><a href="https://i.stack.imgur.com/CmvEl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CmvEl.png" alt="enter image description here"></a></p>

<ul>
<li>Will it works? </li>
<li>If no, why? </li>
<li>If "maybe", under which circumstances will it work?</li>
</ul>

<hr>

<p><em>P.S.: yes! I know that MEGA has three Serials and, as such, I could implement two different BUSses (1: Mega&lt;->Mega&lt;->Mega; 2: Mega&lt;->Nano&lt;->Nano), but this will increase the complexity of the software I'm running, as it needs some hacking in order to play nicely with two distinct RS-485 busses;</em></p>

<p><em>P.P.S.: This is the bus discussed in <a href="https://arduino.stackexchange.com/questions/21932/hardware-network-infrastructure-for-a-fully-arduino-based-home-automation-projec">this other question</a></em></p>
 4143: <p>At low speeds and short distances that won't be a problem.</p>

<p>At high speeds (megabits per second) and long distances (hundreds of meters) you may get reflections unless you get the termination just right.</p>
