Terminal resistor(bus termination)

[Crash_Override]

1.If I'm using the line goes straight out of the console and to only one dimmer.

Is then needed the line end termination (120Ohm resistor between pin2 and 3)?

 

2. The DMX 512 protocol is usually sent by 5-pin XLR connector. If ia contact in both ends the pin 4 and 5, what good or bad will that do?

 

3. Somehow is possible that the console and dimmers communicate () , like dimmers sends data about it's faults, and all other stuff back to console.

How do to that?

Console: Strand 520i

Dimmers: ADB Eurorack 60

 

 

Tervitades,

Tarmo

[david.elsbury]

Hi,

1.If I'm using the line goes straight out of the console and to only one dimmer.

Is then needed the line end termination (120Ohm resistor between pin2 and 3)?

 

<{POST_SNAPBACK}>

Yes. You MAY get acceptable results without, but the DMX-512 specification calls for a terminator to prevent the signal from reflecting back 'down the line'. This is especially important in long DMX runs.

 

2. The DMX 512 protocol is usually sent by 5-pin XLR connector. If ia contact in both ends the pin 4 and 5, what good or bad will that do?

 

<{POST_SNAPBACK}>

Usually, nothing, Pins 4 & 5 are used in DMX-512-A for the devices (dimmers, movers) to communicate to the desk. Some rouge manufacturers use these pins to send power to power desks from dimmers. Therefore, it's often best, in my opinion, to leave them unconnected unless you know your gear requires them.

 

3. Somehow is possible that the console and dimmers communicate () , like dimmers sends data about it's faults, and all other stuff back to console.

How do to that?

Console: Strand 520i

Dimmers: ADB Eurorack 60

 

 

Tervitades,

Tarmo

<{POST_SNAPBACK}>

As I said, that's in DMX-512-A. I don't know if those particular dimmers and desk support sending data back, I would suspect not. DMX-512-A is a very recent development. Do a :) for more info.

 

Check out the Blue Room Lighting FAQ for more info on these and other common questions. And check out the search facility, top right of every page. I'm too tired to find them but there have been other topics discussing this stuff before :)

 

Regards

David

[Stu]

1.If I'm using the line goes straight out of the console and to only one dimmer.

Is then needed the line end termination (120Ohm resistor between pin2 and 3)?

Just reading the ADB Eurorack 60 manual - seems they built in switchable DMX Termination. If you have a look in the manual at Pg13 then it'll explain how to do it. Personally I'd have it switched on, no harm too in my opinion.

 

3. Somehow is possible that the console and dimmers communicate () , like dimmers sends data about it's faults, and all other stuff back to console.

How do to that?

Console: Strand 520i

Dimmers: ADB Eurorack 60

I should of thought you'd need an ADB desk to use talkback features, if the Euroracks allow you to do this. We have ETC dimmers and desk at work, so both can talk to each other through a dedicated link cable (which I must get round to implementing). I can't see anything in the manual about it anyway.

 

HTH

Stu

[Barney]

As Stu said, the Eurorack 60 has switchable DMX termination - it is a jumper on the DMX input PCB at the bottom of the rack.

 

The Eurorack 60 has diagnostic feedback as standard (if the racks are less than a few years old). This uses their ADN (Advanced Dimmer Network) protocol and products. This includes remote programming and monitoring functions. Extended diagnostics functions are available as an option (dimmer circuit loads, comparison to a reference scan, short-circuit and overload conditions).

 

The diagnostic data is normally connected / sent via pins 4&5 of the DMX line, this is normally fine as long as the installation has been planned and installed with this in mind (ie: you need data boosters that work for data on both pins 1&2 and also 4&5, etc.). The feedback data is RS232-based (the same as DMX).

 

It is not possible to provide or use the diagnostics data from an ADB Eurorack on a Strand console. It is normal to have an ADB NetBus connected to the ADN network - this is a stand-alone unit that has the same menu system as the Eurorack. The NetBus provides access to remote programming and test functions easily, and can be used to trigger memories stored on the Eurorack dimmers if required (house lights, working lights, emergency cues, etc).

 

So, in answer to your question, it is not possible to see the Eurorack 60 diagnostics functions on A Strand console. You must use a NetBus dimmer controller, or another Eurorack, to do that.

 

Hope that helps. Let me know if you need any more information.

Barney

[Crash_Override]

what about using the talkback with PC?

[Barney]

Yes, sorry, you are right. You can use the Dimmer Manager software from ADB on a PC.

 

In addition to the functions offered by Netbus, Dimmer Manager provides a graphical representation of the complete dimmer system layout. System configurations can be stored per show, per venue, and off-line editing allows the complete dimmer system to be modified with dimmer parameters uploaded when completed.

 

The PC allows storage of dimmer parameters such as patch, dimmer laws, reference loads, library of custom dimmer laws, which can be uploaded to the system when required.

 

The PC software includes a clock-based memory controller, providing timed automatic playback of lighting sequences if required.

 

The only disadvantage is that you also need to buy a NetPort interface (DMX/ADN to Ethernet) to act as a gateway between the dimmers and the PC. These are reasonably expensive, but the Dimmer Manager software is free!

 

 

... And just to clarify, you would need the NetPort XT interface to do this, not the standard NetPort!

 

Barney

 

Moderation Note: Posts merged.

[chrala]

DMX512 is based on industry standart RS485. As I can remember RS485 _MUST_ be terminated and thus you should _always_ use termination.

 

I think, you might find this site with detail description of DMX interesting:

http://www.dmx512-online.com/physl.html

 

and EIA standards:

http://www.rs485.com/pfaq.html

http://www.eurotherm.co.uk/uk/eng/Knowledg...tions/RS232.htm

 

adam

[Crash_Override]

Didn't want to great a new subject. So I digged up my old one.

 

The line end resistor 120-ohm 1/2 watt.

Must it be 120 ohm's? I don't have the exact match, I found one 220-ohm <-is that to much?

And must it be 1/2 watt? I've found only 1/4 watt and 1watt.

 

 

Standard carbon resistor...should do it?

[bruce]

Didn't want to great a new subject. So I digged up my old one.

 

The line end resistor 120-ohm 1/2 watt.

Must it be 120 ohm's? I don't have the exact match, I found one 220-ohm <-is that to much?

And must it be 1/2 watt? I've found only 1/4 watt and 1watt.

<{POST_SNAPBACK}>

 

Well, 2x220 ohms in parallel would give 110 ohms, which is probably close enough, although not ideal.

 

Power rating - if you must err, err on the high side. The combination of 2x 1/4W 220ohm in parallel would be OK power-wise.

 

Having said all that, my usual supplier sells these resistors at 15p for a pack of 10, dropping to about three for a penny if you buy in bulk....

 

Bruce.

 

Edit: Also, in response to

Just reading the ADB Eurorack 60 manual - seems they built in switchable DMX Termination. If you have a look in the manual at Pg13 then it'll explain how to do it. Personally I'd have it switched on, no harm too in my opinion.

 

I'd take the other option - always leave it off, and use an external termination. I'm thinking back to the days of 10Base2 ethernet networking, where we had none of this new fangled cat5 stuff, and all devices were daisy-chained together using up to 200m of 50 ohm coax and BNC T-pieces. You had to have a 50 ohm terminator at each end of the chain. This was not optional - if it wasn't there, it wouldn't work.

 

Now, some devices had switches for internal termination - but we tended never to use this, even though it worked very well. The reason being that if you were forced to use external terminations, it was always obvious (a) where the end of the chain was, and (b) if a terminator was missing. It also reduced the likelihood of mistakenly adding an internally-terminated unit to the middle of a chain.