Can I daisy chain from 4 port passive hub to another 4 port passive hub?

[FireMedic4Christ]

I think I know the answer, but wanted to confirm with the experts.
 
Prior to DIYL, I had electrical outlets installed on the eaves of my roof. This year I plan to install 4 port passive hubs at each location and use three of the connections for SSC and have one left to daisy chain to the next. The Cat5 runs would be much shorter this way, but does the distance rule still apply if I am injecting power at each 4 port passive hub?

[rrowan]

The 4 port passive hub doesn't regenerate the signal so at some point you will start having data problem. I don't know at what length

Rick R.

[rm357]

No, you should not daisy chain the 4 port passive hubs.

The RS-422 signal we use expects a balanced, terminated transmission line. When you split the signal without regenerating it, it creates a discontinuity that reflects and distorts the signal.

If you want it to work reliably, you need to do something else.

[rrowan]

Funny it has been done and works but since you know better

Rick R.

[FireMedic4Christ]

I assumed I would run into issues at some distance if it was possible. I can get to two of them pretty easy from the SS Hub, but the third run would be much shorter if I daisy chained them. I will try it and see what happens. Worst case I go buy a nice new longer cat5.
 
Thanks
 

The 4 port passive hub doesn't regenerate the signal so at some point you will start having data problem. I don't know at what length

Rick R.

[tbone321]

No, you should not daisy chain the 4 port passive hubs.

The RS-422 signal we use expects a balanced, terminated transmission line. When you split the signal without regenerating it, it creates a discontinuity that reflects and distorts the signal.

If you want it to work reliably, you need to do something else.

As they say, paranoia will destroy ya!  RS-485 is far more forgiving than you give it credit for.  Sure, if you are using it to control the space shuttle then you follow the rules to the letter but for what we are using it for, one or two passive hubs feeding off of each other should work just fine and if not, nothing is going to be crashing into the ground.

[rm357]

It's true, it might work for you.

I stick to the no answer for this reason. When the new person reads your post that says it will, then hooks theirs up and it doesn't, they won't know what the problem is. If they don't have the extra hardware needed to work around it, the bad advice has ruined their plans.

It may work, but you won't know for sure until you hook it up.
If you follow the spec and it doesn't work, you have a failed hardware problem.