10/100 ethernet switch and LOR

[Spud67]

Completly understood. Network adapter is on the way to fix all my questions.

Thanks, have a great week.

[Spud67]

Here is some information I came accross as to why I will need to use the network adapter.

http://www.lammertbies.nl/comm/info/RS-485.html

[Steven]

Frank A. wrote:

You would be introducing signals within the jacketed cable

that would potentially create electrical noise on the opposite

cat5 five circuit --- just not my recommended option --

Sorry, this is a bit off subject... I run 1 Watt of audio through one of the unused pairs in the LOR network cable without any problem. My audio is high impedance, using a transformer at the amplifier and speaker end.

However, someone else used one of the unused pairs to run audio straight from the amplifier to an 8Ω speaker. When he turned the volume up higher than normal, the lights stopped working properly.

The summary: Don't run a high current, unbalanced signal through the unused pairs. If the signal is kept balanced, and at the proper impedance, it should work ok. However, if you send the same signal back the opposite direction, it could be trouble.

[Tim Fischer]

Jeff Millard LOR doesn't use 1 and 2, and passes them through most of the controllers. There's only a couple 8 Channel boards that don't.


So all the 16-channel boards pass the unused pairs through? That's good to know. If I were ever feeling enterprising I'd modify my CTB-08's to do that too... (I've got 10 of the buggers...)

[bphynes]

JBullard wrote:

I wouldn't do it. Just connecting the wires together without a device to provide some sort of isolation, may be detrimental to your controllers.

That layout sounds like a perfect candidate for a couple of the LOR Network Repeaters as already mentioned.

From everything I can see on the boards, the two RJ45 jacks on the LOR controllers are simply connected to the same trace. This makes it electrically like a 1" long Y-cable, doesn't it?

[Max-Paul]

Jeff Millard wrote:

Going with the usual "if it works, then OK! philosophy" What could it hurt to try using an unused pair in a case like this? LOR doesn't use 1 and 2, and passes them through most of the controllers. There's only a couple 8 Channel boards that don't. Knowing this, it might be worth a try to get the 485 signal back through a length of Cat 5 on 1 and 2...

Jeff

At the same time Jeff, some of us are planing to use the #1 & 2 wires for a means to provide some security. Passing a low voltage, low current through these two wires and putting a shorting plug on the last controller to make a loop of the comm cable. You know, you have been active in a discussion of this in a different thread.

Will someone that knows refresh my memory? I know that two wires are not used. Two wires or is it three wires are for the actual comm signals. At least 2 wires have some 10VDC(?) on them for things like the ELL. And either 1 or 2 wires at this time I am not sure of.

[Steven]

bph wrote:

This makes it electrically like a 1" long Y-cable, doesn't it?

When the cable is passing a [relatively] high speed signal, there is a big difference between a 1" Y and a 200' Y. For great bedtime reading, Google transmission line theory. The parts about reflection and impedance mismatch are what is important.

Max-Paul wrote:

Will someone that knows refresh my memory? I know that two wires are not used. Two wires or is it three wires are for the actual comm signals. At least 2 wires have some 10VDC(?) on them for things like the ELL. And either 1 or 2 wires at this time I am not sure of.

For the 8-pin connectors, pin 6 is ground, pin 3 is +10VDC, and pins 4 and 5 are the RS485 signal. For "normally-wired" (486B) cable, pair 1 is the RS485, pair 2 is power/ground, and pairs 3 and 4 are unused.

If the smaller socket is used with 4-conductor phone wire, then all 4 wires are used.

[Salts]

The company I work for sells dust monitors that talk on a 485 network. When a client uses several of these sensors we recommend our network spurs so that they can put many of the sensors together and all be viewed from the a controller/data logger. One of the plants I went to had each sensor brought to a common point with wiring terminals and had then all wired together there without using any of our networking spurs. The systems worked perfectly so I don't see why this couldn't be done. I use a USB485 from my computer to one of my controllers then will daisy chain from one controller to the next. I only have two controllers so that will be easy for me. When I first started I was told that the adapters from LOR were "special" and no third party stuff could be used to talk to the controllers. I used a usb to 485 adapter by ICP that had the 485 part as wiring terminals. I then found the pinouts for LOR and hooked it up. The first try didn't work but it was b/c I had the networking pair reversed. I switched them and it worked great. In the end I still went with LOR USB485 connector b/c it was cheaper and a lot smaller. I borrowed the ICP unit from my work just to see if it would work. With that said a network is a network no matter if the wires come together in a RJ45 jack or on a passthrough wiring terminal at a common point. Spud I would not use a standard hub that is used for home ethernet networking but wiring terminals are cheap. I didn't go that way but as long as it is wired correctly I don't see why it wouldn't work.

Sorry the post was so long just saying that the communication isn't anything new, only the pinouts. If you are not comfortable with it do the safe thing and buy LOR stuff. Heck I do feel comfortable with it and still bought LOR adapters b/c I really like what they are doing and their product.

[Max-Paul]

Thanks Steven,

So that leaves the 1st pair (org) and the 4th pair (brn) open for other uses.

[Jeff Sand]

Be careful whether you're talking about an ethernet hub or an ethernet switch. Ethernet switches, which are most of what is on the market today that people still call "hubs", are smart devices receive ethernet frames and then retransmit them to the appropriate port. Switches will absolutely not work on an LOR network and will probably be damaged if plugged into an LOR controller.

True ethernet hubs on the other hand are simply splitters/amplifiers for for ethernet signal and don't look at the 1's and 0's being passed. You really shouldn't try hooking these up to LOR either because the hub won't be expecting the 10V DC on pins 3 and 6 that exist on LOR. That being said, it's not out of the question that a cheap hub might successfully pass through an LOR signal, but it will probably effectively convert it from a differential signal to a non-differential one (no longer within RS485 spec) and may block the DC voltage bus on pins 4/5, if said voltage doesn't damage the hub in the first place. I would not recommend trying it in practice.

[Steven]

Jeff Sand wrote:

That being said, it's not out of the question that a cheap hub might successfully pass through an LOR signal,

Ethernet uses pairs 2 (pins 3 & 6, green) and 3 (pins 1 & 2, orange). The LOR RS-485 signal is sent on pair 1 (pins 4 & 5, blue). It probably isn't connected to anything in a hub. Also a "dumb" hub will receive on pair 3 and transmit on pair 2, so it wouldn't receive anything from a LOR network. It will attempt to transmit into the same pair that has the LOR +10v power, which is a bad idea.

Gigabit Ethernet uses all 4 pairs, but a Gigabit hub probably isn't made.

[Spud67]

Hey all, just an update.

I received the adapter yesterday and installed it. Everything showed up on the hardware utility and I was able to test all channels.

Enabled the show and wow the house has never looked so good. Going to be a great Christmas.

Thanks for all the informaiton in regards to this.