Revolve control

[alistermorton]

The controller on our revolve has developed a fault. Long story short, it forgets preset positions and won't stop reliably, although it still works with manual drive. The revolve has an encoder and normally it's positionable to within a fraction of a degree. As far as I know, the controller was a one(or maybe two) off. I haven't had a chance to look at the control logic myself (it sounds to me like a failed NVRAM but without looking ...) but at the moment I'm just looking for recommendations for companies who specialise in this sort of control, so we can get some experts in to take a look and maybe get a new control system put in place.

 

I can google, but I'd prefer recommendations.

 

TIA

[Jivemaster]

Without knowing the controller, is there an encoder? Does it collect dirt or dust? OK the chips could be blown but an encoder track being dusty so sometimes not reading right could cause the same symptoms and some cleaner spray may be cheaper.

[bigclive]

A contaminated encoder was the first thing that came to mind for me too. Especially an optical encoder that has got fluff, grease or other liquids in it. This would result in it providing very random positioning results from a starting index position.

 

What sort of feedback does your revolve have with regards to it's initial index position and then subsequent increments?

 

Is it a sensor on the edge of the revolve and an encoder on the motor?

 

I'll just add that this is such a specialised market that it's probably going to be a good idea to try and troubleshoot the system you have at the moment yourselves. These are all very much one-off's so the cost can be very high.

[Jivemaster]

Cheaper correct fixes include finding and cleaning the encoder and the sensors, and finding and paying the original designers. As the system motors manually then looking at the encoder could be a £20 fix(can of cleaner spray) which is the preferred end of the budget range!

 

Starting to reverse engineer the system gets expensive and may not get a solution if there are too many obsolete parts.

 

Try to post the names of useful items, -who designed it and when, who fabricated bits, who installed it and when. Some technologies have been lost as companies close but some technologies are still there inside another company's folio.

[DrV]

I Might be able to help - PM sent

Dave

[alistermorton]

Some useful thoughts, and thanks also to those who have PM'd with contacts and so on.

 

The controller has a readout of degrees on the top of the box. There's definitely an encoder in there, and it has been pretty reliable so far. I haven't seen it since it started misbehaving, but FWIR it started having problems about two weeks ago - it would recall positions for a while, but would lose them eventually (hmm, maybe when the main power was turned off ...) and could then be reprogrammed and work for a while, which to me sounds like a dying battery in an NVRAM but I do know it's had some other chips replaced in the past year or so - one of the display drivers is faulty and that was one of the chips we were unable to easily source, so I'm told. I'll be taking another look at it with the rest of the team soon as, after this weekend's young player's performance, we close over the summer until September for maintenance.

 

Thanks again, everyone, but any further ideas keep them coming.

[bigclive]

Also check that there's not actually a memory backup battery inside. It could be as simple as replacing it if there is and it's failing.

 

Another slightly random thought is whether it actually stored settings when unpowered for any significant length of time in the past. I think it was Siemens who manufactured some logic-brick style PLCs (Logo range) that had the horrific design feature of a memory backup capacitor that would only retain the settings and program (!) for about 24 hours in the event of a power outage.

[alistermorton]

Thanks again, everyone. I had a conversation last night, and it appears that we've been in contact with the original manufacturers who are coming in today to take a look.