ell repeater

[cattlefarmboy]

could you take 2 light linkers and connect them back to back, i know they get they power from the controller, and you would need to supplies the 9v into the cat5. then one would be on one channel and 2nd on another. i have a long way in between 2 houses i want to do this year with running the same show. if that would be possible what are the pinout on cat5?

james

[Max-Paul]

James I can not help you directly. But I wanted to raise an issue that you need to be aware of. First I want you to know that I was a radio repair man in the A.F. 2nd I am an Advance Ham radio Op. Without getting into fancy equipment you will need to still keep these two ELLs seperated. Even though they would be on seperate channels. You will have so much "Bleed over" from the two channels that if one ELL is transmitting, the second would not be able to receive from the far house and your communication will be interupted.

Might I ask, how far away are the two houses?

Just wanted you to understand that the two ELLs can not sit with a few feet of each other. Might have to seperate them by as much as 30 or 50 feet inorder to not receive bleed over from the other unit while it is transmitting.

Sorry if that is a problem, but you need to know before spending the money.



Max

[Guest wbottomley]

James, one pair of ELL's would be sufficient. These units are transceivers.

The distance between the ELL's would be the concern. How far is that distance?

[cattlefarmboy]

the distance between the house is about 1080ft. one house is up on a hill, that one is where my computer runs the show. the other one is down on the road level. i have tried it last month some, it wouldn't get a clear signal. i wish LOR made ELL with removable antenna, so you could use directional antenna with them.

james


Attached files

[Guest wbottomley]

If you or family own the property between those homes, I would run a cat 5 cable between the two.

Get a repeater and place in the middle of the run (http://store.lightorama.com/rsnere.html). In my opinion, it should work.

[Steven]

cattlefarmboy wrote:

i wish LOR made ELL with removable antenna, so you could use directional antenna with them.

I haven't tried this (yet), but I believe you can make the ELL antenna directional by bending a metal plane (from an aluminum soft drink can) into a parabola and placing it such that the ELL antenna is at the focal point. Here is a page that shows the formula for finding the focal point of a parabola. It still may be a stretch to go 1/5 mile.

[Max-Paul]

Ok, RS-485 protocol is a robust protocol, If indeed the LOR RS-485 is a true RS-485 as I am to believe. You can run a TOTAL run of 4000' from the computer to the last device. You are well within that total distance. So, physically this is do able. Now the cost of that much wire might be the prohibitive part of the project. A repeater would only come into play if you plan to put more than 32 devices in a single segment of the run of wire.

Steve your idea of a reflector might be the trick. My suggestion would be for making a corner reflector. A parabolic is rather hard to make. And I am speaking of a true parabolic dish, not an ice cream cone.


On a second look at the diagram. I am seeing a lot of trees. Trees are not a good thing when trying to get a high frequency signal from point mom to point nanny. I cant remember if the ELL is 900 Mhz or 2.4 Ghz. 900 Mhz has a better chance than 2.4 Ghz. But I can tell you that 2.4 Ghz is almost a line of sight only at that kind of distance. Only when you are in a house and less than a few hundred feet does the LOS rule can be ignored.


Max

[Dr. Jones]

if price is no object - I know of a possible solution - mind you i'm talking about $$$$ and it is designed for DMX

RC5 with an amplified antenna



otherwise - aka if it were me - I would buy a spool of cat 5 and make a 1000' long cable ( i found spools of plenum grade - aka disposable- for less than $100 at lowes' last year) and use a lor repeater

[-klb-]

Max-Paul wrote:

Ok, RS-485 protocol is a robust protocol, If indeed the LOR RS-485 is a true RS-485 as I am to believe. You can run a TOTAL run of 4000' from the computer to the last device. You are well within that total distance. So, physically this is do able. Now the cost of that much wire might be the prohibitive part of the project. A repeater would only come into play if you plan to put more than 32 devices in a single segment of the run of wire.

A repeater would at minimum isolate the reflection domains. Depending on the design, it may clean up the signal as well.

As for the 32 device limit, that is 32 standard load devices. The RS-485 chips that LOR uses are 1/8th load on the receiver, so you can theoretically get 8 times as many devices without the repeater.

However, for running a cable from one site to the other, I might be very inclined to use a repeater before leaving the first property for a few reasons. First, it increases the odds that damage to the cable, or noise picked up in the cable won't impact communications at the first house. Second, as long as it is not just an analog amplifier, it should clean up the signal shape before sending it out the long wire.

I might also consider one at the far end as well, just for cleaning up the signal. Of course, if you have the time and patience to troubleshoot, set it up for Halloween as a test. You can see if keeping it cheap with no repeaters works for your purposes, and if not, you can try one, then two repeaters.

[Max-Paul]

Yes repeaters are wonderful things. But they are not self powered right? So now you got to get power some how 500 feet away. Heck even several 100 feet away might be an issue. hence the reason I do not support the use of repeaters just off of the bat. These LOR products should be 100% compatible with the RS-485 standard. With only one exception that I know of. I believe that there is one serial RS-232 to RS-485 adapter that they clearly tell you it is a low power device.

Max

As to that comment about the RS-485 chip. Ok, are you saying that the receive part of the chip draws less or better yet "loads" the signal down less by 1/8th? Then what about the transmit side of the chip? Is it up to normal power output?

[-klb-]

The LOR PC series kit lists two different IC's as interchangeable for the RS-485 chip.

The first is the MAX3082EEPA chip

http://datasheets.maxim-ic.com/en/ds/MAX3080-MAX3089.pdf

The second is the ISL81487LIP

http://www.intersil.com/data/fn/fn6051.pdf

Both provide for full standard drive output, but have only 1/8th of a standard receiver load, allowing for 256 devices on the bus. The CTB16KV6 lists the same two chips, and I expect that the 1/8 load chip is standard across at least the current product line, if not all of it.

As for power, I believe I was recommending one at the first location to isolate the long line from the network of the first house, where the repeater would get powered by the local controllers, and one at the far house, where even if it does not naively accept power from the down stream side, it is close to local controllers and wiring can be adapted to power it locally.

Of course, we never have heard if a cable is a viable answer due to property lines to be crossed or not. But, if the show is going to be run from a PC, there is one other cheaper way to get the network isolation at the top end. Get a second RS-485 adapter, and run the line to the other house as a second network.

[Shubb]

You can use 2 ELL's as long distance relays by having them set to a different frequency, but you have to have a controller in the middle.
ELL at the LOR computer transmits on Freq A. controller in the middle receives on Freq. A then transmits on Freq. B. 4th ELL receives on Freq. B then connects to controller.

My question is, will you be able to "see" the lights from both houses well enough to know the are synchronized? Can you transmit music far enough?

You might want to consider using a MP3 director, or mini director to run the 2nd house independently.

Scott

[Steven]

Shubb wrote:

You can use 2 ELL's as long distance relays by having them set to a different frequency, but you have to have a controller in the middle.

You don't need a whole controller, just a power supply that puts 10 volts DC from pin 6 to pin 3. If they're in the middle of a field, you can use a battery and a regulator.

[Dr. Jones]

Max-Paul wrote:

Yes repeaters are wonderful things. But they are not self powered right? So now you got to get power some how 500 feet away. Heck even several 100 feet away might be an issue. hence the reason I do not support the use of repeaters just off of the bat. These LOR products should be 100% compatible with the RS-485 standard. With only one exception that I know of. I believe that there is one serial RS-232 to RS-485 adapter that they clearly tell you it is a low power device.

Max

As to that comment about the RS-485 chip. Ok, are you saying that the receive part of the chip draws less or better yet "loads" the signal down less by 1/8th? Then what about the transmit side of the chip? Is it up to normal power output?

Therefore you think the use of isolated repeaters over a rs485 network is over rated?

[Max-Paul]

Dr. Jones wrote:

Max-Paul wrote:

Yes repeaters are wonderful things. But they are not self powered right? So now you got to get power some how 500 feet away. Heck even several 100 feet away might be an issue. hence the reason I do not support the use of repeaters just off of the bat. These LOR products should be 100% compatible with the RS-485 standard. With only one exception that I know of. I believe that there is one serial RS-232 to RS-485 adapter that they clearly tell you it is a low power device.

Max

As to that comment about the RS-485 chip. Ok, are you saying that the receive part of the chip draws less or better yet "loads" the signal down less by 1/8th? Then what about the transmit side of the chip? Is it up to normal power output?

Therefore you think the use of isolated repeaters over a rs485 network is over rated?

All depends on the application. In this discussion, the prime problem is to get a control signal from one location to another. Due to distance and the fact that the OP gave us an aerial view of the problem. One can see that there will be enough trees in the LOS that the signal is taking a beating. I believe that the OP said something to the effect that the signal is weak.

And if this was me doing this job, Not only would I be running wire, but I would also be putting it in the ground. Thus less likely to take a lighting hit. As for the isolated repeater. Now you are going to need to mount it in a PED (one of those poles that stick out of the ground that the telco use to splice or tap the truck line). So that the repeater is easy to access to maintain and to make termination. By having it above ground it is unlikely that it will become water logged.

Along the same lines, one should have an isolated RS-485 converter at the computer. And with an isolated repeater, you are going to loose half of your display if not all of it anyway. If the lighting strike is strong enough and near enough, even buried wire can pick up enough impulse to pop electronics. I know. I maintained a fire alarm system at a missle production plant in North St. Charles, MO. I've seen what happens when the gas discharge tube went bad and did not remove the impulse off of the remote pull station wires.

So, No, a repeater should not be required due to the distance of less than 4000 feet. There is also the combined cost and trouble of installing. Ok, I'll take a hit as far as the repeater taking power off of some of the conductors in the wire. Was not aware of how the LOR repeaters worked. Now, would I use one to HELP isolate a possible static charge (from a lighting bolt) from damaging all of my controllers (static charge on one side or the other of the repeater). Then the answer would be yes, along with an isolated RS-485 at the computer if static charge is a concern.

Max

[Dr. Jones]

Max - There is no need to put a repeater in the middle. A repeater at the head of the cable will increase the gain of the signal to compensate for the loss over the 1k feet. I would put an optically isolated repeater on both ends to keep from damaging components in the event of a lightning strike.

If the cable is to be run for longer than a season, then I will have to agree, install it in the ground.

I have a cable that is just shy of 500' and have had no ill effects. it has less than a .5v drop on the output and a slight increase in overshooting on the waveform.

Assuming the cable comes from a controller and ends at a controller, then you should not need a repeater. the repeater is only insurance. From the computer. I believe only the USB RS-485 Booster outputs a hot enough signal to push that distance

[-klb-]

Dr. Jones wrote:

Assuming the cable comes from a controller and ends at a controller, then you should not need a repeater.

You are aware that the LOR controllers only pass through the signal. They do not retransmit the signal at all. A LOR controller probably does a little worse for signal quality than running the cable through a cheap cable coupler.

[cattlefarmboy]

i found out on mistaken that you could take off the top antenna. i was thinking about ordering http://www.l-com.com/item.aspx?id=20230 to connect the 2 houses, that way i woundn't need to run a long cable or use a controller in the middle. i was also wondering if anyone else know what connector is on the the linker, and if i need a RP-SMA plug for the antenna connector.

thanks james

[Max-Paul]

Iwas told that the ELL radios are on the 2.4 Ghz band. With that if it is true, then you will need to use one of these. Either the 12 or 15 dbi gain antenna. Look at these http://www.l-com.com/item.aspx?id=21869

Then you might need one of these depending on the connector on the ELL.
http://www.l-com.com/item.aspx?id=5348

You do not want to extend the coax cable from the antenna. At this high of a freqency and more cable extended to the antenna and the loss of signal in the cable will take away any gain you get from the antenna. So you will need a water tight box mounted just below the antenna. Then run some Cat 5 to this box from your RS-485. You will want to keep this run as short as possible too.

Not knowing the difference in height between the two houses and how clear the view is once the leaves fall from the trees. I predict you are still going to have a hard time getting a good link. There is a reason that they say you need a good line of sight between the two antennas when working with 2.4 Ghz and above. Also a little known fact of non-radio people is this, and I do not remember at this time the take off angle. But not only do you need the ability to see the other antenna. But the further apart they are the higher above ground they need to be. What I am refering to is this, there is a ice cream cone radiation pattern that radiates from the antenna. And is at its largest at the mid way point between the antennas. If something blocks part of this pattern, even if it is below a laser line between the two antennas. It will degrade the signal. Now I am not talking about short range like 200 feet or less. It becomes more critical the further out the two radios are from each other.

You might only need one, or two or mabye neither will work. But it will be cheaper than the wire. Besides sounds like you already have the two ELLs. The antennas are not that much more to invest. Besides, bet you can unload them on Ebay with no problem..

Disclaimer, The suggested adapter to go from female N to SMA male is just a possible required adapter. You will need to find out what actual connector is on the ELLs and order acordingly.

Max

[Max-Paul]

Really good Doctor, what benifits do you presume to achieve by putting a repeater at the head of the cable? Do you really understand what the purpose of the repeater is?

Let me explain a few things about the purpose of a repeater is. First lets look at a different repeater my good man. Radio prepeaters such as us hams use them on the 2 meter band and other bands. If I put a repeater up in the middle of a city and a mobile units is on the north side, they then by the use of the repeater can talk to a mobile unit on the south side of the city. Now, lets say I had put the repeater on the north side of the city. The north mobile unit can access the repeater and due to its higher wattage and usually its antenna is on the top of a 2 or 3 story building. The mobile unit on the south side can hear the repeater. But the mobile unit with lower power and with its antenna closer to the ground is not able to be received by the repeater. Thus the north side mobile unit never hears the south side mobile. So, what was gained by having the repeater near the head of the cable?

Now if you put an isolated repeater after the last controller at his mom's house and a isolated repeater before the first controller at nanny's house. Then I see that you are trying to keep any static charge that might be induced in the long run of cable between the two houses. And that I can understand. But your reason for doing so for the signal strength or voltage drop is, well wrong headed. As I have stated before, RS-485 is good for 4K feet. But like anything else. You should use cable that is rated for RS-485 duty. Meaning you would not put 50 ohm impedence cable on a TV antenna. And you would not put 4 ohm speakers on a stero rated for 16 ohms. If you do on either above examples. Then your system will develop a degraded picture or sound.

You sound like a learned man. I presume you used a scope to look at the single. Cause you mention that the voltage overshot some kind of reference. That is from the L and C componets of the wire that has caused a shift in voltage and current of the signal. But I presume you tuned your probe before hand. Even your probe will give you a false reading if you do not tune it to the frequency of the device under test. A 1Khz square wave will not work for tuning to something that might be very well in the 1Mhz.

I think that is enough for you to chew on for now. And my fingers are getting tired too..

Max
Dr. Jones wrote:

Max - There is no need to put a repeater in the middle. A repeater at the head of the cable will increase the gain of the signal to compensate for the loss over the 1k feet. I would put an optically isolated repeater on both ends to keep from damaging components in the event of a lightning strike.

[snip}

I have a cable that is just shy of 500' and have had no ill effects. it has less than a .5v drop on the output and a slight increase in overshooting on the waveform.