Reef Angel Forum

I was having relays in my main and expansion box turning off and on when they should be either on or off steady. I found the rapid red status light blinking. I removed the usb expansion cable and the blocked bus light went away but my main relay box would cycle port 1 about every 2 seconds. Port 1 controls my heater which is on at 76.8 and off at 77.0. The relay clicks and the temperature reads 76.8 then 2 seconds later clicks again and the temperature reads 77.0. The temp reading always goes 76.8-77.0-76.8-77.0 etc. I've checked the svga cable for connection tightness. USB to expansion module is disconnected. T2 and T3 is disconnected as well as the ph probe. The head unit is about 3 months old and connected away from the sump and higher. No salt creep or trace on the head unit. Also my salinity module went to 6.0 just before all this happened. I do plan on picking up a spare svga cable and a couple usb cables for testing.
Any thoughts would be appreciated.

Did you try increasing the range?
76.8 and 77 is a very tight hysteresis.

ebbtide wrote:... which is on at 76.8 and off at 77.0. The relay clicks and the temperature reads 76.8 then 2 seconds later clicks again and the temperature reads 77.0. The temp reading always goes 76.8-77.0-76.8-77.0 etc.

My RA does the 0.2 degree fluctuation from time to time as well. It think it has something to do with the bus but I haven't been able to nail it down. I think I'm getting interference with some of the 110v powered device cords being too close to the USB cables possible. Could also be solar flares I haven't had time to really dig in to it.

Resetting all the cables, especially the USB cables, seems to resolve the issue most of the time. Every once in a great while I just have to wait it out. It'll go back to normal after a day or two usually.

~Charlie

It's still a very tight range and regardless will cause the relay to on/off more than you'd want. I usually go with .5 degrees

That would certainly mask the problem. I've been running a .2 hysteresis for close to 2 years. The only time it's an issue for me is when the bus goes wonky on me. When that starts happening it typically locks up port 5 on my 2nd relay box as well.

I kind of use the rapid on/off of the heaters as an indicator that something is wrong with my RA as well which is a small part of why I leave it like that. The plan is to figure out what is causing it and correct the real problem! Just need to find the time to find the problem...

As a side note, this problem is generally triggered when I'm moving things around under the tank or in my RA cabinet. It very rarely happens out of the blue.

When I first installed my RA I noticed that the pH and temp readings were nice and smooth, after about a week they became kind of jagged looking with lots of small variation noise by +/- 0.2 or so. I assume it's something I added to the tank that is generating the noise or something I hooked up to the RA that isn't properly isolated, but I'm not sure what it would be.

It is a close differential but as Piper said I too have been running this for quite awhile now with no problems. Everything seemed to be running great till a couple of days ago. First the salinity seemed to be going down. I tapped the probe to release any trapped air bubbles but to no avail. Next it just went to 6.0 which is I think the default for no connection. Then the blocked bus light started flashing. I disconnected everything except the temperature probes and this is the end result. On off cycling of the heater outputs. Whats really strange as I mentioned in my last post is the temperature displayed does not go from 76.8 to 76.9 to 77.0 With each relay click it bounces from 76.8 to 77.0 back to 76.8.
OK I'll go with the solar flare for today, go home and change my svga and usb cables, widen the differential and upload the code. And hope for the best.

One thing I've seen is that some of the sensors are tricky. They do not always hold a steady number and when you look on the screen which is redrawing every few seconds, you don't see the changes each millisecond or every run of loop().

As far as things going wacky, I had a whole day that I was getting bus locks and luckily it was the calcium doser that got stuck on and not the alk one. I only ended up raising my calcium by 100ppm. That night after troubleshooting, I reseated the connection to my RF module amongst other things, and updated the firmware with the test one (from another post) and have been problem free since that night. I've been hand dosing since then, but getting ready to go back to automated method, because it gets pretty tiring and I hate having to do this manually. If I don't dose twice a day my alk dropps at least 1dkh without supplements...