Replacing Long RS232 Runs with Ethernet for Projector Control

[shayward]

Hi Everyone

I've been asked quite a few times (especially in PMs) about controlling projectors over long RS232 runs. I do a quite a bit of long-distance RS232 runs (including a 4300km run... yes, that's 4300 kilometers, from Washington state to Ontario).

The best way I've found is the use of a Serial Server. A serial server allows you to use your existing network (or a new network) for RS232 communications. Networks can span 100s of feet or 1000s of miles. Serial Servers don't care.

The best serial server I have found is the Moxa NPort 5110. It's industrial grade, readily available, meets various standards (CE, FCC, UL, ULC, RoHS), unbelievably easy to configure in 5 minutes, reliable, and costs about $100 US last I checked. I spent two months with a competing product that cost twice as much and never got it working. I had my first NPort 5110 working in under 10 minutes. I have a bunch running at locations world-wide and most haven't been rebooted in years. Any that were rebooted it was because they were unplugged for no particular reason.

Here are the diagrams:

Moxa NPort 5110 - 1.png

Moxa NPort 5110 - 2.png

Moxa NPort 5110 - 3.png

There are other scenarios I haven't tested but will. I've got to order another half-dozen for R&D.

- Shaun

[babson philip]

HI mr shayward.
thanks for your encouragement i love that. mr shayward i will like to talk to you privately consighning my church audiovisual equipment problems. this is my mail address i wil like you to send message in for reply. and love to read from you as soon as possible. babson philip

[babson philip]

e-mail add-; babsotech audiovisual @ gmail.com, lawson boy 4real @yahoo. co.uk joint all the gaps

[Nandus]

Moxa Boxes are good
in the hospital they use them to connect blood glucose meter to the Hospital Information System

[shayward]

Originally Posted by Nandus

Moxa Boxes are good
in the hospital they use them to connect blood glucose meter to the Hospital Information System

Hey, if it's good enough for a hospital...

[babson philip]

i am still looking for the solution on how to control multiple projctor online. incase anybody knows about this i need an help

[pdc]

Networking projectors is simple. You use the built in network card ( or PCMCIA if it is a portable or RS232 if it is older), and a unique IP addressses and your LAN.

[randystevens]

Have you had any reliability problems using the network approach? I am weighing the differences between using the network approach and RS232 for controlling 3 Optoma projectors.

[shayward]

Do the projectors you're looking at have built-in web servers and allow control from a browser?

Ethernet is solid and stable. So is RS232. Both have their pros and cons.

With Ethernet, all you need is a network ($50 LinkSys router) and a computer with a browser. Every computer these days has a browser from Mac to Linux to Windows and beyond. You may even be able to use the browser on a Wi-Fi equipped mobile phone. So there's never any work about software.

The down side is that you will have to repeat each action 3 times and there will be an obvious "studder" as you go from projector to projector.

If you have an RS232 control solution that will allow you to take action on all 3 projectors at once, no studder (or at least very little studder).

But the down side of that is that you need some special hardware and software.

My recommendation is that when you do the cabling, do two CAT5e (or CAT6) runs for each projector. CAT5e cable is CHEAP. Maximum run is 300' (100m) for Ethernet. The other cable will be for RS232 control. You can either try connecting DB9 ends to the cable and running raw RS232 over them or you can use a Moxa NPort 5110 or similar device to send the RS232 signal over your network.

This way, you are not locked into using one means or the other.

Plus you can always start with the web browser approach and if you don't like it you can look into other solutions.

- Shaun

[randystevens]

That would be an interesting approach to build in both methods. I think in our case we are also running the video over cat5/6 cable so that would mean 3 cables per projector. It seems as though the ethernet method would be easiest. I am just not clear why Optoma would say that most people use RS232 because it's more stable especially since they build the web control in. With the serial approach, I believe I will need more hardware plus software to control the projectors.

[shayward]

Perhaps when they say "more stable" they really mean "more mature". RS232 is, after all, several decades old in common use in everything from industrial equipment to a/v equipment. But if you think of the quantity of "blue cable" that makes up the vast majority of wired networks (home, corporate, and internet)... there really can't be much of a reliability issue.

Unless they don't trust their own web server tech

Yeah, 3 runs to each projector should do the trick. I just bought some cute ends the other day that go from RJ-45 to DB9. $4 CAN each and you can control the wiring.

Are you familiar with RS232? Kicking around on CMN somewhere is a guide I've written. It's not finished but it certainly should give you a good starting point. I believe the link to it appears in this thread. Make sure you get the latest copy (I think v0.5).

[randystevens]

It's been a while since I've had to make any serial cables. Back in the day when we used dumb terminals with a mini-mainframe.

I'm like you, i don't really understand how the ethernet option wouldn't be stable. Unless it would need to be "rebooted" occasionally. That would be a problem because these projectors are going to be about 20 to 25' off the floor.

Thanks for the help.