AVS › AVS Forum › A/V Control & Automation › Home Automation › Crestron Systems - Programming?
New Posts  All Forums:Forum Nav:

Crestron Systems - Programming? - Page 3

post #61 of 108
TPS-5000L on its way to my house. I'm hoping the lack of an Ethernet card won't hurt me too much, for learning programming.

Don't have Crescat. I'll use 2 2-conductor cables, 18g for power, 22g twisted for control, both stranded.
post #62 of 108
Thread Starter 
Quote:
Originally Posted by Neurorad View Post

TPS-5000L on its way to my house. I'm hoping the lack of an Ethernet card won't hurt me too much, for learning programming.
Don't have Crescat. I'll use 2 2-conductor cables, 18g for power, 22g twisted for control, both stranded.

Seems like it would do, they are 18 and 22 from what I can remember. the 18g wires for data/control are actually shielded as well as a twisted pair. Could be because power runs through the same cable? In my opinion though if you have 2 separate cables, then it really won't make much difference because you're separating the power and control by doing that anyways. Other than that, the specs are pretty much the exact same for Cresnet as far as I can tell.

Let me know how you do. This thread is a nice place to visit for little bits of information every once in a while. I just read the Yahoo group stuff, haven't yet posted in that category for discussion. Maybe if I have a question that requires a larger range of opinions from other Crestron enthusiasts out there, but until then, this forum has been great! I've bookmarked this forum a long time ago and haven't had any regret on doing that lol.

Good luck smile.gif
post #63 of 108
I've done a tremendous of reading, but I don't recall the use of the Cresnet shield drain wire. Is it usually connected to the controller chassis ground? I don't think the shield will serve much purpose without that connection, but I don't recall reading anything about that connection. Is the connection doubled with the Cresnet control pair ground? I wouldn't think that would be a good solution, as a foil shield is usually connected at 1 end only.
post #64 of 108
Thread Starter 
Quote:
Originally Posted by Neurorad View Post

I've done a tremendous of reading, but I don't recall the use of the Cresnet shield drain wire. Is it usually connected to the controller chassis ground? I don't think the shield will serve much purpose without that connection, but I don't recall reading anything about that connection. Is the connection doubled with the Cresnet control pair ground? I wouldn't think that would be a good solution, as a foil shield is usually connected at 1 end only.

We're not even using that ground wire in the building we're doing all these installs... You would actually pair it up with the power though and have it go to somewhere where it can be grounded. Double it up inside the phoenix connector. We did something similar actually at the DMC-T course training. What do you mean about that shield not serving much purpose though? How come?

What's sent through the Y and Z is data, although i'm assuming it's for interference protection because of the fact that power runs right beside it inside the cresnet coat... Could be wrong though, but I know this is taken into consideration when running video, and probably other things too.

EDIT: If you're interested I could probably show you a picture if I could find that Cresnet cable we made at the DMC-T training. I'm pretty sure we were using ground there with the larger black phoenix connections. When you're only running low voltages though, it isn't quite as critical I would think, however for good practice i'm sure it should be implemented.
post #65 of 108
I'm under the impression that a shield is only useful if it's grounded, but I really don't know. I also think the shield is to protect from nearby AC, and not the adjacent DC power.

If the connector was grounded, e.g. for STP, the instructions are quite explicit. I'm just not sure of the proper use of a Cresnet drain wire.
post #66 of 108
Thread Starter 
Quote:
Originally Posted by Neurorad View Post

I'm under the impression that a shield is only useful if it's grounded, but I really don't know. I also think the shield is to protect from nearby AC, and not the adjacent DC power.
If the connector was grounded, e.g. for STP, the instructions are quite explicit. I'm just not sure of the proper use of a Cresnet drain wire.

AC over DC yes, because alternating is more likely to interfere, but current is also going in the opposite direction from which the data is being sent back to the controller, so i'm not sure in that case. I don't have much information on how they got the specs for Cresnet either. But what I imagine, power sent through Cresnet is to allow powering up a device, in which in turn, sends data back through Y and Z to the controller for it to do something on anything on the OUT, whether that's IR or Serial out, etc...

Although the purpose of shielded cable basically keeps all the electrons in the flow within that shield so that nearby equipment and all that isn't affected if in the case something does happen with electrical shock. This is I believe, usually the reason why a shielded bundle of wires comes with a ground inside, because if you're grounding for any purpose, you'll have to dispose of all that electricity someplace, and to keep it on a good path and not have it affect anything else nearby, that's what that shield does. And you'll see Cat6 and Cresnet included where the ground wire is just stranded wire with no coating if it's shielded.

My father was a Test engineer that did all the electrical work at Nortel when it was at it's high point. He would probably be able to give more answers to me about all this stuff if I was curious enough to ask. I'm not an electrician, just an AV guy smile.gif But i'll learn all this stuff eventually. It's good to know, and just because i'm not an electrician doesn't mean I may not need this kind of information.

~Ace
Edited by AceInfinity - 9/18/12 at 8:26pm
post #67 of 108
Thanks, Ace. I've done some reading, and shield definitely reduces DC transmissions into and from the conductors.

And, grounding the shield is much better than ungrounded.

I think I'll eventually invest in some Cresnet, but I'll make do with what I have on the test bench. I have a feeling that the majority of my devices will eventually be on a LAN, and not connected with Cresnet, anyway.

I cannot find the specification for the number of twists, for the 22g control pair. I don't think that will be an issue for testing, so I'll shelve that discussion.

I'll leave shield ungrounded for now.
post #68 of 108
Thread Starter 
Quote:
Originally Posted by Neurorad View Post

Thanks, Ace. I've done some reading, and shield definitely reduces DC transmissions into and from the conductors.
And, grounding the shield is much better than ungrounded.
I think I'll eventually invest in some Cresnet, but I'll make do with what I have on the test bench. I have a feeling that the majority of my devices will eventually be on a LAN, and not connected with Cresnet, anyway.
I cannot find the specification for the number of twists, for the 22g control pair. I don't think that will be an issue for testing, so I'll shelve that discussion.
I'll leave shield ungrounded for now.

If it works it works smile.gif What i'm using is not Cresnet specifically, but I did start with the Cresnet wire that came with the devices initially. Then later on, because they only give you a ridiculously small length, I swapped my Crestron Cresnet out with some other cable which is being used in place of Cresnet where I currently work, and it works.

As for good practice I would've thought so as well, gounding better than ungrounded haha. Good practice too, even if you think it's not needed as i've said. I think it would be more beneficial to go LAN though. I have a faint suspicion that this is the way our future is headed in AV anyways. All IP and wireless communications. Now that integration with your iPhone or your iPad, ect... Is now possible. It's a popular trend, and for that reason, things will sway that way in my opinion.

~Ace
post #69 of 108
I'll try 18/2 plus 2 conductors of 22/4. Doubt the twists in the security cable are sufficient to match the specs of Cresnet, but it won't be an issue on the test bench.

Yeah, seems all new devices are networked on a LAN.
post #70 of 108
Quote:
and shield definitely reduces DC transmissions into and from the conductors.

DC does not transmit nor interfere with anything. I't sDC, it's static, it cannot radiate.
The electrostatic shield surrounding the wires is transparent to electropmagnetic interference. The data transmitted on a the cable is balanced/differential, noise will be cancelled out by the receiver.
Quote:
AC over DC yes, because alternating is more likely to interfere, but current is also going in the opposite direction from which the data is being sent back to the controller, so i'm not sure in that case.

The data is RS485...bidirectional.
Supply current travels in both directions, to and from the load. It's DC though, so no interference is possible.
post #71 of 108
Thank you, Sam.

Static DC - not rectified, constant.

I read somewhere that DC can cause EMI. Maybe with rectified DC? Changing amplitudes -> changing field?

I've dug through a lot of RS485 literature, off an on, the past few years. Doesn't the amplitude of the voltage change - the basis for signalling?
post #72 of 108
Thread Starter 
Quote:
Originally Posted by SAM64 View Post

The data is RS485...bidirectional.
Supply current travels in both directions, to and from the load. It's DC though, so no interference is possible.

Ahh, but i've heard it is only based on RS485, and not that it is actually RS485? It runs at a non-standard rate which S-to-E adapters probably would not support. Also multidrop, thus its functionality isn't supported by those adapters.
Edited by AceInfinity - 9/21/12 at 5:23pm
post #73 of 108
Thread Starter 
Is the CrestronLabs forums still open (edit: Removed link just in case I shouldn't be posting a link to an external forum here)

Or Active? I've been registered for more than a week or two now, but no activation in order to see any of the forums. Does anybody still go there, or am I wasting time waiting because it's a dead forum? confused.gif

I found it through the Yahoo Crestron group, and seen about how they activate members, but I still haven't been activated yet...

Also, I got myself a PCI-Express card with 2 serial/RS-232 ports, and a parallel port extension that came with it. Now I can see if I can set my MC2E up over LAN, but in the meantime I can still upload via the way I know how. It seems MUCH faster than Serial to USB conversions though through the previous adapter I had.
post #74 of 108
I'd call Crestron Tech Support to inquire further, if you feel that it will help you. From my understanding, it's for beta software discussions, for advanced programmers.
post #75 of 108
Thread Starter 
Beta "software"? for Crestron programming in itself? That IS my thing lol. If it's programming directly related to the software used when programming with Crestron, then that's what I mainly do. Software development. smile.gif I'm used to the whole:
Code:
if (something(x, 10))
{
        //do this
}

Syntax instead of the the logic blocks in SIMPL Windows. I'm actually curious to see when they start coming out with more programming libraries for Crestron programming. I've heard rumor about C#. smile.gif

Back on topic though, I have contacted them twice now, but no response back and i'm still not activated frown.gif
Edited by AceInfinity - 9/23/12 at 1:20pm
post #76 of 108
Quote:
I read somewhere that DC can cause EMI. Maybe with rectified DC?

Rectified DC is still DC, rectified AC is also DC.

The cresnet cable consists of 2 DC power conductors and a balanced data cable.(RS485)
The DC cannot interfere with the Data because it is DC.
The Data signal could be induced into the DC conductors, but will be removed by any capacitance in the circuit, with there will be plenty of ,in the power supply.
post #77 of 108
Thread Starter 
Good information SAM64 smile.gif I'll keep this in mind. I don't know why then, but I've been told to separate DC from power by others lol. I guess I can stand up against that now and tell them why it doesn't matter tongue.gif

Others however, have also told me that since it's DC it doesn't matter, but playing the safe game I took that into consideration anyways and tried to keep the power and data separate. I know with AC it matters, unless rectified AC as you say...
post #78 of 108
How can you separate DC form data in a cresnet cable?
Same with POE. It's DC it cannot cause any interference.
This is basic electronics.
post #79 of 108
OK, Sam, thanks for clarifying. Much appreciated.

I love learning about electronics. In another life, I'd be a EE.

Many Cresnet control cable alternatives, from most cable manufacturers.

West Penn 357
Belden 1502r
Belden 5302GE
Belden 9155

For a few feet, I don't think the shield or twists are important, though. The shield is to prevent EMI to the control pair.

But to be thorough - what would the drain wire connect to, for the shielded pair? Controller 6-32 screw chassis ground? It's very close to the Cresnet adapter.
post #80 of 108
Thread Starter 
Quote:
Originally Posted by SAM64 View Post

How can you separate DC form data in a cresnet cable?
Same with POE. It's DC it cannot cause any interference.
This is basic electronics.

How to separate DC power? By not making a DC power line side by side with Cresnet itself? (or any other data line for that matter) confused.gif But separating DC from "Cresnet"??? I didn't make a reference to Cresnet in my post, you assumed that. I understand what Cresnet is--If you read my previous posts in this thread, you'll see that I mention Cresnet being Red/Black Power, and the other 2 wires are data. Why would I try to think of splitting the coating on Cresnet to separate them?

That's what i'm trying to say here though... You don't have to try to belittle me just because you aren't understanding what i'm trying to explain. There's external (DC) power supplies we are using alongside cresnet and Cat6 for video feeds. They want us to separate that external DC power cable from all others (and what i'm also trying to say is that this is what I don't understand; what they are trying to get us to do by separating DC power from the data)... I'm not talking about Cresnet here. If you read closely I did not mention "Cresnet" even once in that post here: http://www.avsforum.com/t/1424101/crestron-systems-programming/60#post_22428762

Just some ounce of respect and more tact in your replies is all I ask for. Your posts seem a bit hostile that's all.
Quote:
This is basic electronics.

You've mentioned that DC can't cause interference, but here:
Quote:
How can you separate DC form data in a cresnet cable?

?

Overall misunderstanding i'm sure, so i'll let it pass. Although it seems it wouldn't be the first incidence where your apprent aim instead of helping is to target one others intelligence where you see fit:
http://www.avsforum.com/t/1429770/upgraded-to-latest-metallic-hdmi-connectors-noticed-improved-picture-and-sound
http://www.avsforum.com/t/1414167/new-to-commercial-audio

And all i'm trying to do here is learn, and to do so, keeping an open mind is least foolish. You didn't wake up and gain every last bit of knowledge you have today, so provide some patience with others trying to get there as well.

Cheers,
~Ace
Edited by AceInfinity - 9/24/12 at 5:02pm
post #81 of 108
Quote:
Originally Posted by AceInfinity View Post

Is the CrestronLabs forums still open (edit: Removed link just in case I shouldn't be posting a link to an external forum here)
Or Active? I've been registered for more than a week or two now, but no activation in order to see any of the forums. Does anybody still go there, or am I wasting time waiting because it's a dead forum? confused.gif
I had to escalate to get my registration to go through. Like yours, it sat there.

The forum itself is not too active but what is there is direct answers from Crestron people.
post #82 of 108
Quote:
Originally Posted by SAM64 View Post

How can you separate DC form data in a cresnet cable?
Same with POE.
Crestnet has separate wire for DC like some versions of POE, but not all. It is not phantom power if that is what you are thinking. So you can do what he is doing in using separate power cable and data although I would not do so for customer systems (Crestron will likely not support you if you don't use their combo cable).
post #83 of 108
Thread Starter 
Quote:
Originally Posted by amirm View Post

I had to escalate to get my registration to go through. Like yours, it sat there.
The forum itself is not too active but what is there is direct answers from Crestron people.

Yeah, I finally got in, funny thing - I was awarded the 7 day registration achievement before I even got activated to realize that I had it haha smile.gif
Quote:
Originally Posted by amirm View Post

Crestnet has separate wire for DC like some versions of POE, but not all. It is not phantom power if that is what you are thinking. So you can do what he is doing in using separate power cable and data although I would not do so for customer systems (Crestron will likely not support you if you don't use their combo cable).

True, and I know we don't, perhaps for no other reason other than cost reduction? But it's essentially the same kind of wire. No visible differences other than the coating is black instead of green/yellow. Shielded twisted pair for data 22 gauge, and 18 gauge for the power. I have a length of that thick blue Crestron cable here at home from the DMC-T training still, and that's what i've just been using for all my tests, other than a small bit of the extra stuff we're using as a substitute for Cresnet cable that I brought back to use, because the smaller test samples they gave out in those packages that come with Crestron devices were a bit too short for me to do much with.
post #84 of 108
My touchpanel 'arrived' yesterday, but nobody home to sign for it. :/

Hopefully UPS will be able to get a signature today.

It's stated very clearly in multiple Crestron manuals: 'Use Crestron certified cables.'
Edited by Neurorad - 9/25/12 at 7:15am
post #85 of 108
Thread Starter 
Quote:
Originally Posted by Neurorad View Post

My touchpanel 'arrived' yesterday, but nobody home to sign for it. :/
Hopefully UPS will be able to get a signature today.
It's stated very clearly in multiple Crestron manuals: 'Use Crestron certified cables.'

They would love for you to buy and use their cables yes smile.gif Whether there's reason for it which is justifiable 'enough' or not? They will justify that. Of course there are differing opinions out there i'm sure, I for one haven't dealt enough with Crestron to see where it's crucial to use their wire. I did witness a small issue though with not using their DVI cables for projector inputs in a board room though not too long ago, but it was probably a length issue between the differing manufacturers. Crestron's were a tad shorter in length from the other's in use apparently.

I suppose if you're playing it safe, Crestron cable were built to spec based on their own equipment, so it should be most fitting logically; (ideally/hopefully anyways).
post #86 of 108
Quote:
The shield is to prevent EMI to the control pair.

The shield is transparent to electromagnetic interference. The differential receiver cancels out common mode noise on the data lines.

Quote:
I've been told to separate DC from power by others
Quote:
How to separate DC power? By not making a DC power line side by side with Cresnet itself?

Why does crestron specify a cable with DC and data side by side, if it's bnecessary, according to you, to seperate DC and data?
Quote:
Overall misunderstanding i'm sure,

yes, on your part.
Quote:
Crestnet has separate wire for DC like some versions of POE,

yes, I'm aware of this.
There seems to be great concern here about 'interference' form DC....how is that possible?
post #87 of 108
Quote:
Originally Posted by SAM64 View Post

The shield is transparent to electromagnetic interference.

In my limited understanding of shielded cables, I'm under the impression that the control pair shield helps reduce EMI that can be caused by AC power cables. If not this, then what is the purpose?
post #88 of 108
back on topic please

posts deleted
post #89 of 108
Quote:
I'm under the impression that the control pair shield helps reduce EMI that can be caused by AC power cables.

the differential receiver cancels common mode induced noise.
post #90 of 108
Differential receiver...you mean utilizing the twisted pair? I don't think differential signaling relies on a ground reference - that's the advantage over single ended signaling.

Oh, you're saying that the shield doesn't protect from induced noise, that's the job of the twisted pair and differential receiver?

So, then what's the purpose of the shield, for the Cresnet control pair?
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Home Automation
AVS › AVS Forum › A/V Control & Automation › Home Automation › Crestron Systems - Programming?