Strand AMX Dimmer System

[thelightguy87]

I'm helping troubleshoot a high school dimmer system. Its a 48ch CD80 Dimmer Rack. It was connected to a Stand MANTRIX console. Simple 2 scene preset. This system was installed in the mid 80s I believe. But just a week or so ago, the Mantrix console took a turn for the worst. And now when you power it on, ALL the lights turn on, and the only way to turn them off is to turn off the console. This console is connected to the dimmer rack via an AMX 4 pin connector.

As a replacement console we brought out an old first generation ETC Insight console. This console has AMX output connectors and DMX output connectors. We plugged the AMX cable into the console and no light will turn on, when putting everything to full. I changed the dipswitches on the console for AMX192 to AMX384, reboot the console and nothing happened. In the bootup sequence it says that the AMX output is active.

We tried everything we could think of to get this to work with no luck. My only theory left is that maybe the pinout of the CD80 dimmer rack is different than the console. Is that likely?

I've read through a few other posts about AMX seeing that you need to make your console know what kind of dimmers its using. Any idea how to do that on an Insight? they are all 2.4k dimmers on an old CD80 with no processor.

I'm not familiar with AMX at all. I'm just helping the auditorium manager who is less versed than I am in lighting systems. So any help is gladly accepted.

Thanks,

 

[Gern]

...
As a replacement console we brought out an old first generation ETC Insight console. This console has AMX output connectors and DMX output connectors. We plugged the AMX cable into the console and no light will turn on, when putting everything to full...

Did you make sure there is a patch in the Insight; like maybe 1-1 channel addressed to dimmers?

Also, As I understand it, the tiny AMX connectors are a notoriously poor design, and disliked by many. They are prone to come apart, as one did yesterday on my stage. If there is a loose connection in there, or they have been damaged, they can affect the signal. Carefully inspect your AMX line for any damage.
My DMX to AMX converter caused all the dimmers controlled by its first universe to randomly flicker. When the Local 40 shop swapped the converter, that's when they touched the AMX connector and it came apart. When we go on our next hiatus, they will install new jumpers & the larger XLR4 pin connectors.

 

[thelightguy87]

Part of the original install is a wallmount 4pin connector labeled Dimmer 1 and another labeled Dimmer 2.

The Mantrix was setup with a large 4pin xlr and a tiny 4pin T connector to go into the board.

So in this situation with the Insight, there is no small T Connector.

Yes the patch is 1 to 1. I even did a full diagnotic reset. And checked every systems menu I could find that would relate to the problem I'm having.

After reading this post. http://www.controlbooth.com/forums/lighting-electrics/4436-strand-mantrix-manual.html#post48616 I plan to make an adapter. If by swapping the pins around fixes my problem, I will be good to go.

 

[jstandfast]

Yes indeed, those of us who had to deal with the TY-4 connectors on a regular basis came to hate them mightily. Steve Terry has said it's the worst
electrical connector foisted on our industry, ever.( ST I hope I'm quoting you accurately here.) On a more practical note : the pinouts on the TY-4 and full size 4 pin XLR are different for AMX-192. I don''t recall the detail, but you've a size change in connectors anywhere, be suspicious.

 

[venuetech]

Doug Fleenor's webpages have an amx192 pinout page

http://www.dfd.com/pdf/amx192pinout.pdf

 

[derekleffew]

...I've read through a few other posts about AMX seeing that you need to make your console know what kind of dimmers its using. Any idea how to do that on an Insight? they are all 2.4k dimmers on an old CD80 with no processor. ...

I think what you may have read is that the console needs to be told the location of 6K dimmers when mixed in a rack of 2.4 s. If no 6K s are present, no need to worry about this step.

In the few instances (in the 1980s) I've tried, I had no issues controlling CD80 s from ETC consoles with AMX192.

For more on AMX192, see Pathway Connectivity Inc. - Lighting Control Protocols - Part 2 :

AMX192 and D54
History - Strand's extremely popular Light Palette consoles and CD80 dimmers first appeared in 1979, and with them came a new multiplexed analog control scheme that would later evolve into USITT AMX192. It was soon incorporated into Mantrix consoles and Environ architectural dimmers; in fact, virtually every North American Strand product designed until very recently included at least one AMX port. As well, a number of their competitors made compatible products over the years. Strand's R&D group in the U.K. devised a somewhat different analog mux protocol they designated D54 (an internal standards number) to work with their Galaxy and Gemini control desks. D54 never made inroads into North America, but it ended up everywhere else in the world. On the other hand AMX192 is virtually non-existent outside of the U.S. and Canada, yet it was applied to a wide range of dimming and control product over the years, by a number of different designers and manufacturers. An unfortunate consequence is that many of these products are not entirely interoperable, even within Strand's own product lines.

Details - Depending upon the type of console, a single AMX192 data line can handle either 96 or 192 dimmers. Dimmer levels are sent sequentially on one wire, referenced to a signal common wire that the other conductor is paired with. A synchronizing clock signal is sent differentially on a second pair of wires. When AMX first appeared on Strand products, it used the tiny Switchcraft TA4 connector. Its pinout was clock- on pin 1, common on pin 2, clock+ on pin 3 and mux analog on pin 4. Suffice it to say (with understatement) that the TA4 was not the greatest connector choice Strand ever made. Many users, especially rental shops, couldn't wait to replace it with the tougher 4-pin XLR. If they'd waited a bit longer, though, they would have had a standard XLR sex and pinout provided by USITT in the AMX192 standard that appeared in 1985. Instead, there's a lot of gear out there that uses the wrong connector sex and the TA4 pinout. This is how it should be: input connectors are female and outputs are male; pin 1 is common, pin 2 is clock+, pin 3 is analog, and pin 4 is clock-.

D54 is easier to describe; it runs over 2 wires, a signal conductor that carries both the dimmer levels and the clock signal, and signal common. it uses only 3-pin XLRs and one pinout: common on pin 1, no connect on pin 2 and signal on pin 3. 384 dimmers are supported.
Both AMX192 and D54 use 0-5 volt dimmer levels.

Interfacing Hints - Anyone who has dealt with AMX192 gear for any length of time will tell you that they've had more than their share of problems getting things to communicate properly. No one console, for example, will talk to all receivers out there, and vice versa. The age and condition of receiver cards and power supplies can affect how well the data link works. The type and length of cable can also be a factor when changing to a different transmitter, such as a protocol converter. Just because your old Mantrix worked fine with your old CD80, it doesn't mean your new converter is no good because it doesn't. Designers of new AMX controls usually pick a set of signal timing parameters that are known to work well with most of the existing dimmer racks; you might just be one of the unlucky ones that gets a mismatch. Ask your supplier to let you test other makes of converters; at least one is likely to do the job.

 

[nimblebrain]

I'm helping troubleshoot a high school dimmer system. Its a 48ch CD80 Dimmer Rack. It was connected to a Stand MANTRIX console. Simple 2 scene preset. This system was installed in the mid 80s I believe. But just a week or so ago, the Mantrix console took a turn for the worst. And now when you power it on, ALL the lights turn on, and the only way to turn them off is to turn off the console. This console is connected to the dimmer rack via an AMX 4 pin connector.

As a replacement console we brought out an old first generation ETC Insight console. This console has AMX output connectors and DMX output connectors. We plugged the AMX cable into the console and no light will turn on, when putting everything to full. I changed the dipswitches on the console for AMX192 to AMX384, reboot the console and nothing happened. In the bootup sequence it says that the AMX output is active.

We tried everything we could think of to get this to work with no luck. My only theory left is that maybe the pinout of the CD80 dimmer rack is different than the console. Is that likely?

I've read through a few other posts about AMX seeing that you need to make your console know what kind of dimmers its using. Any idea how to do that on an Insight? they are all 2.4k dimmers on an old CD80 with no processor.

I'm not familiar with AMX at all. I'm just helping the auditorium manager who is less versed than I am in lighting systems. So any help is gladly accepted.

Thanks,

strand AMX ocasionally reversed the order of its pin out. try swapping the clock plus and minus lines at the rack. if that fails buy a dove convertor ( yes i think gary still does that ) AMX was proprietary to Strand, and sometimes other mfg. AMX wont work. sorry.