Quantech Appcon kit - UK

It's where I would start, though. Look for burn marks, blown caps, leaky caps. What did the board cost to begin with? I ask because I am contemplating doing a similar thing and want to know if I should just factor in the cost of buying my own spares, even for $$$ units.

Go to Ebay and set up a standing search to alert you if someone places a board like this up for sale. Don't cross your fingers. Search Google for any terms unique to the board or the system. Sometimes people sit on piles of stuff like this.

Tell us more about the sensors and other devices you have hooked to your network. It sounds like the Dallas 1 Wire components might make suitable replacement sensors if you're determined to reuse your existing code.

What type of loads are you switching and what do you use keypads for? It will help determine what type of replacements would be suitable.

I'd say this is a very unrealistic expectation given that it's not likely you'll find a replacement board. What language is it written in? What are functions are tied into the system? Porting isn't that difficult for some languages.

I wouldn't use X-10 for something like this, especially since you're just starting out and have a world of better, more reliable protocols to choose from. I'm still not sure what to recommend because this is more that just a HVAC control system.

-- Bobby G.

[snip]

It really depends a lot on the types of existing sensors. Are they 0-5V,

4-20mA, other...

I would take a hard look at something like the picoFlash from JK Micro.

It's not capable of running Linux but I don't think you need that at this level - embedded DOS is reliable. You can talk to this over Ethernet from your Linux system.

For more money you can get embedded PCs that can run Linux. Take a look at Technologic Systems. You can probably find European systems that are similar.

While you can control X-10 directly from your PC, I would not invest much in X-10. Insteon is a newer PLC system that looks to be far more reliable. While it's not available for 220V there are plans for that.

ISTR it was about 50GBP for the controller about nine years ago.

There are temp sensors, Open/Close sensors and mains switching up to a couple of hundred watts - Fine for central heating pumps etc. I have one of the open/close boards in front of me and apart from resistors etc it has two chips a ST93C46CB1 94E440 & a PIC16C54C 9919HAJ whatever they do :-)

As above - couple of hundred watts at most. Keypad is to give commands to the system from living area - Change heating levels etc. One of the tricks I got it to do which the wife loved was as the PC is also our answer machine she could type a code on the keypad and it would play back the messages over its sound system. I also use text to voice so the system responded with voice to commands and status readouts.

It's C - it has hooks that feed data both ways to other programmes. For example a CGI script can query variables in the program on the fly and say put the current temperature on a web page. There are functions that depend on it being dark or not. I run a perl script that calculates sunrise/sunset and pumps the two times into the control system. So the garage door sensor will turn the lights on if it is dark but not in the daytime. I am sure it would work with a different system. As long as *something* can read temperatures and switch states and turn mains on and off then the control logic should be fine.

I have an electronics clued up friend and he has gotten the board power supply sorted that had been giving problems, but sadly it looks as though something else is broken as polling the RS232 interface does not even give an echo! Ho Hum.

One is EEPROM (probably used to store configuration data) and the other is a microcontroller (the brain). I think you are dead in the water unless you can fix the main controller or find the communications protocol that the main controller used to communicate with other boards. There's no reason for EEPROM and a microcontroller unless the open/close board has some degree of independence from the main controller. Without knowing what and how to say to the open/close board and others like it, you'll likely need to replace everything.

That's unfortunate because the cost of a spare would have been way less than anything you're going to put together to replace it. You've inspired me to re-evaluate my own spares policy, particularly concerning devices that spiderweb through the house. They are likely to take induction hits from nearby lightning strikes, etc.

I'm not sanguine about any of these items being reusable. When you say Open/Close sensors are you talking about valves, windows, doors or what?

Pretty easy to replace but probably not at a price you're going to like.

The problem I see is that most of the controllers that would replace your unit have their own programming languages. Your control logic could be ported to a new system, but not without a lot of rewriting, I fear.

Obviously your best bet is to fix that board or find a replacement. Good luck!

-- Bobby G.