RK2/Serial Adapter/PH Problems

[izib]

Im using a USB to Serial adapter to hook my RK2 into my laptop. It works great until I plug my powercord into the wall. When I plug the laptop in the PH jumps way up. Is anyone else having this problem? Better yet, does anyone does of a solution?

Zach

 

[dough]

I would look over in reefcentral under the sponser forum. There is bound to be something there. Also post your question there. DA checks that site.

 

[cameron]

This is a common problem with RK2 systems. The temp probe is picking up interference from the DC powersupply being run from AC. I believe they are using a thermistor, and I suspect that the problem is the result of poor analog circuitry design. They might be able to fix it with software filtering in an upcoming patch. Another possible way to fix this is to clip all the wires but the relevant two leading to the PC. Someone was going to try this and see if it worked, but I haven't heard back.

The solution as of now is to use a different computer with a better shielded powersupply.

 

[sprayin70]

I think DA has a software update on their site that will fix that. But again I don't know if it will work. Good luck

 

[izib]

Ive tried a new dell laptop, a new hp laptop, and a couple year old dell desktop. All are giving me the same thing. Cameron, do you think clipping the wires could work?

Ive found it on reefcentral but no real advice.

 

[cameron]

It could, but depends on the feedback going into the system. Usually a different desktop machine fixes temp and ph fluctuations. Haven't seen somebody who went through so many machines with the same problem. Could be the wiring itself perhaps.

 

[izib]

Im running 2.4 although I wasnt when I tried the desktop. I might try it again tonight. I think I might try cutting the wires too.

 

[george]

I was going to try doing a wire isolation test on the theory that since the splitter they include is just a phone splitter, it might suffer the same line crosstalk that you'd get if say a computer was connected via dial-up and someone picked up the line. I was going to create a new cord to connect the computer that dropped the upload line on the serial connection. This would necessitate having the fully wired line still available to do firmware updates.

However, I don't recommend cutting wires on the original equipment. Get a 6 wire phone cord and clip it or a replacement 6 wire splitter. It was suggested that the temp monitor communicates on the same lines so clipping the wires may cause communications problems and might cause you to not be able to update the firmware.

 

[cameron]

Didn't want to out you George as the line cutting tester just in case you didn't want the PMs. George did make a really good point that two read only wires should be able to read the RK2 output without creating any loops. As he suggested, I would get a different cable before hacking my original one up as it might not work and I seriously doubt you would be able to update firmware if you were successful with a hacked up cable.

 

[george]

Well, since I managed to cure my case of "stupid" by noticing that my RK2 was only at 2.1 firmware and needed 2.4 to do data logging, I should be able to test this more this week and this week-end.

 

[izib]

Looking forward to seeing what you find George. I might play with it tonight myself.