7/9/2007 8:07 PM | |
Posts: 22 Rating:
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Hi Fux, Well this is what I figured out myself but didn't get any further... I still don't know how to limit the value to 7,0 to 8,0. I have to click a lot to get to the 7,20... What I would like to do is: I would like the logo to keep the pH value of my pool constant. I can measure the pH value already. The pH has to stay at 7,20, that's perfect. When to high, I have to put a certain amount of acid in the pool to lower the pH. So I want to preset this value of 7,20 into the Logo and compare it with the actual measured value. I want to measure this once a day, when the main pump is running. I thought using a comparator and compare the two signals and use the output to run a small pump for a certain time to pump the acid. The more the measured pH is off the preset value, the bigger the diffence is (comparator),the longer the pumpruns to put the propper amount of acid into the poolto bring the pH down. Hope you understand what I mean... Do you have a good plan Fux? Kind regards, Arne. Attachmenttest3.zip (942 Downloads) |
Last edited by: Arne at: 09.07.2007 21:18 |
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7/10/2007 4:10 AM | |
Posts: 191 Rating:
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Hi Arne!! ¿¿ do you want to keep the Acid pump working until the PH is inyou Set Point range ?? ¿¿ do you needto modify the Set Point ? irecomend not to use the cursors as a way to modify theSP... if your LOGO is running and you have the day / time screen press the ESC key, then go to the Set param option and press OK here you can see and modifythe parameters you have programed.. i think this is muchbetter than using the cursor keys... please simulate the program i´m sending and see if you like this approach if you want to change the High and Low limits just get into the Set param option... have a nice day!! ROSA Attachmenttest4.zip (846 Downloads) |
7/10/2007 7:43 AM | |
Posts: 22 Rating:
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Hi Rosa!... Yes, I was thinking the same. I'm not too sure if it's wise to preset the pH by cursor buttons... I only have to set the preset value once. Well this part of the logo should work like this: In the morning the main pump starts circulating the water through the filter. After, say about an hour or so, I will measure the pH-value. I wait for some time to get this sample because I think you will get a more accurate reading after the water havecirculated for some time. Ifa that momentthe pH-value is the same as the preset value (7,20), nothing will happen. If themeasured value is too high, I have to determine how much too high to determine how much acid I need to get the pH to the preset value again. So how much is it off the preset value... To lower the pH for 0,1 point per m3, I need 10mL acid per m3, give or take... First I thought about a couple of timers. Then I thought that it also should work with a comparator and compare the two values, and have the output of the comparator set the time the acid pump should run. Well after I have determined how much the measured value is off, I will let this acid pump run for acertain time. If the pH is just a little off, the pump will have to put a little acid in the pool, more off I need more acid in the pool to lower the pH. This "pump running time" has tobe adjustabledepending on the acid and thevolume the acid pump can pump in a certain time. After the acid pump has given the pool this shot, it will stop. Thewater will have to circulate for some hours before you see the actual result and can have a accurate reading to check the pH. How long the water has to circulate, I don't know... The main pump has to circulate to filter the poolvolume twice a day. In my case the pump will start in the morning, run for say about 4,5 hours, then stop for a couple of hours. In theevening it will run again for say about 4,5 hours. I'm not sure to measure this pH-value twice a day (1 hour or soafter the main pump starts) because I'm not sure this 4,5 hour will be sufficience to "mix" the watergood enough... So maybe it's a good idea to only measure the pH once a day, in the morning. Well Rosa, what do you think about that?... Kind regards, Arne. Attachmenttest1.zip (954 Downloads) |
Last edited by: Arne at: 10.07.2007 07:44 |
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7/10/2007 10:14 PM | |
Posts: 191 Rating:
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Hi!! try this example... it still needs some programming for your application, but i think this is what you are looking for.. tell me if there is any doubt!! ROSA Attachmenttest3.zip (972 Downloads) |
7/11/2007 5:11 PM | |
Posts: 22 Rating:
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Hi Rosa, Yes, it is. Thanks! This is a good base to work from. Again thanks a lot. Kind regards, Arne. |
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