Howto: PLC Reef Controller II

For all you having troubles finding a PPI cable, there are two on ebay right now. Me, I am looking for a thermal couple, some "S word" and relays. anyone have any laying around please let me know. I am tring to keep this tread going now you all have me hooked.
 
What are you guys using for a pH monitor that will tie into the Analog Input? I have all ao my hardware ready to go for complete reef control except for a pH monitor.
 
I am starting to set up a controller for my system and was wondering what to use for a temp probe? I have a 0-10 volt input to work with. I did some searching but did not want to buy somehting that would not work.

Thanks
 
OK, back at it.....
This weekend I'm going to try to get the lights working via PLC (AB), will post some prelim. ladder logic after I debug it a bit more, and will be looking for some comments/feedback.
Have fun :)

RV8tor - My employer was recently awarded a project using an S7 series PLC, the software is in, just haven't started on it yet. I should be pretty familiar with the specifics of the S7 in short order. I did use an S5 series, but that was a bunch of years ago.
 
marm64 said:
I am starting to set up a controller for my system and was wondering what to use for a temp probe? I have a 0-10 volt input to work with. I did some searching but did not want to buy somehting that would not work.

Thanks
Click to expand...

Check out http://www.omega.com/. They have quite a bit of process control equipment for a decent price. They also send you cool Dilbert cards with your order... :rollface:
 
tide_ben said:
Check out http://www.omega.com/. They have quite a bit of process control equipment for a decent price. They also send you cool Dilbert cards with your order... :rollface:
Click to expand...

You could get the thermistors at Omega, I actually have one of their temp controllers with a thermocouple. The problem with using a thermocouple with your own controller is that you would also need to get a cold junction wich adds to the cost. The reason you need a cold junction is to compensate for the difference in materials between the thermocouples wires and the connector on your controller. With thermistors you dont have that problem and they work well for the temps we are dealing with.
 
Would you really need the accuracy of cold junction correction? With the temperature swing inside your house you'd probably only be correcting a hundreth of a dagree.
 
I would use an RTD for temp, more acurate than a T.C.

I am glad to see someone else interested in this. I have been working on automating my 180 gallon for a while.

I am using a Allen Bradley PLC. I have a
foxborro PH and Cond. transmiter. I have wrote a program that I will enter sunrise and moon rise times for the whole year, and it will simulate a natural reef within a min. I am now working on getting a always on internet conection so I will be able to use remote desktop to monitor and control my aquarium from anywhere.
 
slug said:
Would you really need the accuracy of cold junction correction? With the temperature swing inside your house you'd probably only be correcting a hundreth of a dagree.
Click to expand...

Actually I wouldnt use the cold junction for accuracy. More for stability of the reading. Ive tried getting readings without using a cold junction, and I could never get a stable voltage from the TC.
 
I was going to originally try out a PLC, never had a chance to work with one yet. But I designed a controller for a well monitoring system (for a work project) so I figured Id just use that.
 
yea!!

I thought this thread was going to die. Glad it isn't.

RIBS - Thanks for keeping me in mind, I know zero about this PLC biz, but want to learn for the tanks sake.

I am still searching for S/W for the S7 series that I don't have to pay an arm and leg for.
 
WY_REEFER said:
Here is a temp transmitter that would work good.
http://www.omega.com/ppt/pptsc.asp?ref=TX250&Nav=temn03

You can change 4-20 mA to 1-5 volt with a 250 ohm resistor.

Then you just scale your PLC to read 1-5 volt.

Here is an RTD that would work good with that transmitter.
http://www.omega.com/ppt/pptsc.asp?ref=PR-10&Nav=temc03

Or keep your eyes on ebay for a cheaper one.
Click to expand...

Saw this post, just wondering if you can explain how and where to add the 250ohm resistor. Ive been searching for a way to get 1-5v scalable voltage from a ph transmitter that sends 4-20ma. My controller will only use 1-5v.

Thanks
Don
 
I agree with recent thread comments about this being nice to have some active participation here with thread watchers hopping in and stuff.
 
You must log in or register to reply here.

Similar threads

I
3d printing a tangential venturi for needlwhelll valves
Replies
4
Views
3K
Dr RBG
Dr RBG
slief
500 gallon reef.. Possible Tank Breakdown and looking for buyers
2
Replies
28
Views
4K
Anarez
A
H
The Return of Hans - A 150 Gallon SCA Mixed Reef Build
4 5 6
Replies
113
Views
72K
hhaase
H
dodgerblew
Everything for sale
2 3
Replies
56
Views
7K
dodgerblew
dodgerblew
Wally.B
My Tank Thread (Take3) ★Total AUTOMATION★ DIY Doser, Sump, AlgaeScrubber, WaterChnges
47 48 49
Replies
979
Views
220K
Wally.B
Wally.B
Back
Top