Manual PID tuning oddities.

[BitterSipper]

I am trying to manual tune my PID controller. I have got it to a point much better than what the AT got it to (AT made everything terrible actually.).

I'm following this short guide. Problem I'm having is with I and D off, the temp is rising past set point, but the controller STILL gives it a little bit of power and it settles high or continues to rise. From my understanding it shouldn't be giving any power with I and D off when the value is over the set point.

 

[P-J]

BitterSipper,

It would help a lot IF you would identify your PID. We have NO clue what you are dealing with otherwise.

Wishing you good luck (You need it).

P-J

 

[BitterSipper]

BitterSipper,

It would help a lot IF you would identify your PID. We have NO clue what you are dealing with otherwise.

Wishing you good luck (You need it).

P-J

It's a mypin TA4 but to my understanding that shouldn't really matter except for specific values, the logic should be the same regardless of the actual controller.

 

[Sideways]

I've had the same experience with the mypins. They don't tune like the should. Your best bet is to replace it if you want proper PID control.

 

[P-J]

It's a mypin TA4 but to my understanding that shouldn't really matter except for specific values, the logic should be the same regardless of the actual controller.

For me it does matter.

I'd like to help but you seem defiant enough and with that you are on your own from my point of view, I have no clue what you are dealing with. No link or details. Hmm...

Oh well. Good luck.

P-J

 

[RSNovi]

Adding some I should help with the steady state error that I think you are describing.

 

[schematix]

Adding some I should help with the steady state error that I think you are describing.

Funny thing about 'adding' I-gain... Does that mean increasing the value? Depending upon the controller (that he hasn't told us about), 'adding gain' could make it more aggressive, or less aggressive. Depending how the controller expresses its gains it could go in the opposite direction. Often times its a multiplier in the denominator so a higher value makes it softer.

 

[augiedoggy]

change the "I" to "1" leave all other settings at default and it will work fine and learns fairly quickly.... no need to autotune... I run 4 of these ta7 and TD4 mypins and they work just as well as the chinese auber pids sold at 2 -3 times the price despite the people making biased assumptions who likely did not have them setup correctly....

 

[Sideways]

Let me add to my previous statement about the Mypins I have that do not working correctly. In no way am I biased and yes, i know how to tune PID controllers. It was a significant part of my education and i am responsible for tuning at my employment. Maybe the 2 controllers I have are faulty but they are 2 different models ordered at 2 different times. I certainly wont ever buy a 3rd. The OP is correct about overshooting the setpoint. Even with no jntegral or derivative the controller will output 100 percent even after the setpoint is exceeded. Thats not supposed to happen.

 

[JONNYROTTEN]

For what its worth I have the aubrins 2352.I ran auto tune and got no where.I set at around 164 for a 152 mash stirring every 10 minutes or so.It seems to be correct with a thermometer in the mash

 

[Sideways]

For what its worth I have the aubrins 2352.I ran auto tune and got no where.I set at around 164 for a 152 mash stirring every 10 minutes or so.It seems to be correct with a thermometer in the mash

Did you run autotune while mashing? The controller will purposefully overshoot the setpoint during autotune

 

[JONNYROTTEN]

Did you run autotune while mashing? The controller will purposefully overshoot the setpoint during autotune

No I AT with an empty pot and 10 gallons of water while on the phone with Aubrins...didn't work.someday Ill try again

 

[augiedoggy]

Well I can only speak for my experience... I also install and service equipment that uses pids but this does not make me any type of expert on them.

The 4 mypins I purchased were bought from 3 different sellers. mine do not overshoot they may hit a degree or two over for portions of seconds but the pid quickly learns and corrects and within seconds it is able to maintain the desired temp. I see often here that when an inexpensive product does not appear to work correctly the people are quick to blame the product when often its something thats not understood correctly about the products setup or operation... I just saw this yesterday with someone bashing the DC pumps (luckily that person later posted that his issues with the pumps were from a faulty powersupply.. but that person was so quick to blame the pump that he had bought multiple replacements and claimed they were all junk and suggested buying a chugger instead...
Its frustrating when you have a lot of firsthand experience with these very same products and do not ever see these Issues....

I also saw the same thing friday in a cereal killer grain mill thread somone was quick to say the mill doesnt work and is a piece of junk... They stated the handle "doesnt work" and slips...when I inquired that when its assembled correctly with the set screw locked down against the flat machined into the shaft they then stated they have no such flat... the owner also stated that his handle was missing the locking nut on the set screw but apparently he thought that was there just for looks? he stated he threw away his handle and even though its been brought up a couple times that he should post pics of this shaft without the flat in it the poster seems to now be sidestepping the issue claiming he has already bought a drill handle so its a "moot point"

You can see how this can make one skeptical when someone makes general statements about multiple examples of a product...


I was given advise here to simply change my "i" setting to 1 because my "mypin pids " also overshot when at default because I do not always use them for the same amount of same gravity liquid I also switch between the pids without turnng the power off to them so while say the HLT element has been shut off because I switched the controlling relay over to the BK element the HLT pid is still trying to adjust to reach its setpoint it will do this the whole time I'm boiling with the other pid. Also, from what I have read and understand of pids they would need to be "reautotuned" everytime I switch volumes between 5 and 10 gallons. Instead, once I changed this single setting I found they now work GREAT with no autotuning needed... Isnt that the point of what the OP was asking?

I find it funny that when something is expensive and doesnt work as it should then everyone blames it on operator error or some other issue. Yet its usually the opposite when its a cheaper product like here. usually everyone who owns the expensive stuff uses threads like this to post the I told you so comments about how top dollar parts such as what they have is needed THOSE people are often biased and sometimes trying to justify their own decisions. To them the world is flat and price always dictates quality.The reality of the real modern marketing and distribution practices does not exist to them..
Auber pids are made in china as well yet many of the owners of these pids seem to often be quick to mock others as "chinese junk" and imply the aubers are american made and this is why they cost twice as much...All you seem to hear about here is Aubrins is an American company... Everyone leaves out the facts that point to aubrins really being a distributor of the same chinese products from the same factories as the chinese stuff on ebay and amazon..just sold at a 35-100% markup due to the additional middleman.
Just look at this recent thread about an aubrins pid thats "Not working correctly"
https://www.homebrewtalk.com/f170/pid-help-517397/

 

[BitterSipper]

Adding some I should help with the steady state error that I think you are describing.

Yes I have experimented with this and it does help some, but what I'm trying to confirm is whether or not the controller is acting correctly in the first place. To my understanding I and D disabled it should not be trying to heat at all when above the SV, but that it can oscillate around the set value while being on average or continually below it. For some reason the controller continues to heat some while over SV and the temp is staying continually above, not even oscillating to below the SV, let alone on average.

Funny thing about 'adding' I-gain... Does that mean increasing the value? Depending upon the controller (that he hasn't told us about), 'adding gain' could make it more aggressive, or less aggressive. Depending how the controller expresses its gains it could go in the opposite direction. Often times its a multiplier in the denominator so a higher value makes it softer.

He wasn't saying to increase the specific value of I. He was expressing it in a way independent of actual values. I understood what he meant, and as I understand it you are correct, on most controllers, using a lower value is what he was suggesting. I did however state earlier the controller I have is a mypin TA4.

change the "I" to "1" leave all other settings at default and it will work fine and learns fairly quickly.... no need to autotune... I run 4 of these ta7 and TD4 mypins and they work just as well as the chinese auber pids sold at 2 -3 times the price despite the people making biased assumptions who likely did not have them setup correctly....

I may give that a try, but "learns fairly quickly"? I don't think they "learn" when not in auto-tuning mode unless you mean the oscillations subside because of the integral, but I wouldn't call that learning really?

Let me add to my previous statement about the Mypins I have that do not working correctly. In no way am I biased and yes, i know how to tune PID controllers. It was a significant part of my education and i am responsible for tuning at my employment. Maybe the 2 controllers I have are faulty but they are 2 different models ordered at 2 different times. I certainly wont ever buy a 3rd. The OP is correct about overshooting the setpoint. Even with no jntegral or derivative the controller will output 100 percent even after the setpoint is exceeded. Thats not supposed to happen.

Mines not doing this, on P only it correctly gives 100% while very low from SV, then it starts to taper as it gets closer to SV like it should, but then after going over the set value it still gives 1-5% and holds the temp above/climbs the temp more from SV. Regardless, my understanding is it should not be doing this.

For me it does matter.

I'd like to help but you seem defiant enough and with that you are on your own from my point of view, I have no clue what you are dealing with. No link or details. Hmm...

Oh well. Good luck.

P-J

If that's your attitude then good riddance. I gave a straightforward answer to your question, so if it matters to you for some unknown reason than that's fine, but like I stated the controller model itself should have no bearing on the answer to my question as I was not asking specifics.

 

[schematix]

If that's your attitude then good riddance.

I take offense to the tone of this entire post. We're all just trying to help. Good luck - I'm out.

 

[BitterSipper]

I take offense to the tone of this entire post. We're all just trying to help. Good luck - I'm out.

So, guy announces he thinks I'm defiant and doesn't want to help (despite my straightforwardly answering his question). There's really only one type of person/reason to announce to people you're not going to help, and that's because you are a spiteful person and hope others will follow suit (this isn't a very good personality trait).

So after saying I don't really want the help of that type of person anyway, you decide that you're going to also announce that you don't want to help because this "offends" you.

I'm sorry the both of you don't appreciate my pointing out that you are missing the question, which doesn't revolve around any particular model controller and your not understanding what RSnovi was saying, but really, I think you should reflect on your personal feeling and attitudes and why you find it necessary to announce to anyone that will listen that you're "out", because it's truly a pitiful personality trait.

 

[BrotherGrim]

So, guy announces he thinks I'm defiant and doesn't want to help (despite my straightforwardly answering his question). There's really only one type of person/reason to announce to people you're not going to help, and that's because you are a spiteful person and hope others will follow suit (this isn't a very good personality trait).

So after saying I don't really want the help of that type of person anyway, you decide that you're going to also announce that you don't want to help because this "offends" you.

I'm sorry the both of you don't appreciate my pointing out that you are missing the question, which doesn't revolve around any particular model controller and your not understanding what RSnovi was saying, but really, I think you should reflect on your personal feeling and attitudes and why you find it necessary to announce to anyone that will listen that you're "out", because it's truly a pitiful personality trait.

I don't believe that anyone here is being petty or mean with intention to cause an issue. I have gotten great assistance and advice from the members of this board.
You just happened to ignore advice from one of the most helpful people on this board. The effort and advice P-J has put into this forum has been phenomenal to say the least. His expertise and assistance has inspired and guided many of us over the years. You can choose to do what you will, but if you go back and read the any of his previous posts and topics that he has contributed to you may realize that this man is "The Expert" on this topic.

Please don't turn this into a flame war when all that was intended was to help.

 

[augiedoggy]

I don't believe that anyone here is being petty or mean with intention to cause an issue. I have gotten great assistance and advice from the members of this board.
You just happened to ignore advice from one of the most helpful people on this board. The effort and advice P-J has put into this forum has been phenomenal to say the least. His expertise and assistance has inspired and guided many of us over the years. You can choose to do what you will, but if you go back and read the any of his previous posts and topics that he has contributed to you may realize that this man is "The Expert" on this topic.

Please don't turn this into a flame war when all that was intended was to help.

I am not sure of this and someone please correct me if I'm wrong but I have gotten the impression from many threads that PJ may have some sort of affiliation with Aubrins. (Theres nothing wrong with that of course if its even true).. Many times when people ask for help and it comes out that they didnt buy from aubrins he has basically stated he "thats too bad" in some form and thats the end of it. Often if they state right from the get go that its a non auber brand component he rarely comments at all but when he has he basically says the same thing about there being no documentation for them with the same type of tone.. (spiteful or not)

The only reasons for this I can think of is the only products he has used and is familiar with are from them(which is possible but he seems almost too knowledgeable for that type of limited exposure. ) or he possibly works for them in some capacity..In all fairness we dont come across the really expensive brands like Watlow on here much at all unless someone gets them for free or damn close so. I could very well be completely wrong and PJ may just not want to bother helping support a product that has poor English support from the manufacturer and I can also understand this.

Again maybe I'm wrong but its the impression I have gotten from his comments. No doubt that he has been extremely helpful here in the development of this type of brewing... And theres also no doubt that the documentation for these pids is not very good however it is online as others have linked the pdf page to these pids before when questions like this have come up before... do a search here or google and you will find those threads just as I did when I bought my first mypins..

 

[BitterSipper]

I am not sure of this and someone please correct me if I'm wrong but I have gotten the impression from many threads that PJ may have some sort of affiliation with Aubrins. (Theres nothing wrong with that of course if its even true).. Many times when people ask for help and it comes out that they didnt buy from aubrins he has basically stated he "thats too bad" in some form and thats the end of it.

So in other words, even though the actual model of controller didn't matter to answer the question it "mattered to him" because he only helps those with aubrins controllers? The attitude makes more sense now.

I don't believe that anyone here is being petty or mean with intention to cause an issue. I have gotten great assistance and advice from the members of this board.

Please don't turn this into a flame war when all that was intended was to help.

There are plenty of people here being helpful and I am responding in kind with them. I am not "ignoring his advice", he offered none, all he offered was a resolution that he doesn't want to help after I answered his question, presumably in a way he didn't like. That's nearly the definition of petty as there's zero good reason to respond that way/at all except to be spiteful.

There's no reason to discuss this further, it's not the topic at hand.

edit; In the interest in not fueling this further I'm just going to add this here. Today I learned, the 3rd post and first possible opportunity is "much later on" :smack: Sigh, and this is not supposed to be petty?

 

[augiedoggy]

I may give that a try, but "learns fairly quickly"? I don't think they "learn" when not in auto-tuning mode unless you mean the oscillations subside because of the integral, but I wouldn't call that learning really?
.

I should have said compensates and adjusts to correct the oscillations very quickly not "learns"

 

[P-J]

augiedoggy,

I do not have an affilation with Auber Instruments. I use and am familiar with their products. Also, I have helped many others in their planning when they have chosen a different PID for their system. The problem I encountered in this thread was the fact that the PID was not identified until much later on - After I gave up on supporting the OP.

Anyway.

Wishing all the very best.

P-J

 

[augiedoggy]

augiedoggy,

I do not have an affilation with Auber Instruments. I use and am familiar with their products. Also, I have helped many others in their planning when they have chosen a different PID for their system. The problem I encountered in this thread was the fact that the PID was not identified until much later on - After I gave up on supporting the OP.

Anyway.

Wishing all the very best.

P-J

OK, thanks for clearing that up.

As far as the information you asked for not coming out until much later in the thread I don't see how you came to that conclusion myself..
The Op asked for information on PID logic in the first post From what I understand he was thinking that the "P, I and D" settings all meant the same thing regardless of which brand he might be using...( As is my understanding too)

You asked for the information in the second post in this thread (you had already shown frustration here by wishing him luck and telling him he would need it therefore casting the first stone no?
The Op gave you the answer in the very next post 30 minutes later... and went on to explain that he didn't think it mattered since his questions were about the PID settings and how they effected performance. I think this whole thread started out on the wrong foot and escalated over nothing..

 

[Gameface]

A few things of note, Auberins PIDS do not cost 3x as much as Mypin PIDS. The 2352 PID costs $46.50. A quick search for a Mypin TD4 shows prices from $39 to $24. So while the Auberins do cost more, they are not ridiculously more expensive.

Also, I think the logic does vary from model to model. As do people's experiences and best known practices. So the model DOES matter.

 

[augiedoggy]

A few things of note, Auberins PIDS do not cost 3x as much as Mypin PIDS. The 2352 PID costs $46.50. A quick search for a Mypin TD4 shows prices from $39 to $24. So while the Auberins do cost more, they are not ridiculously more expensive.

Also, I think the logic does vary from model to model. As do people's experiences and best known practices. So the model DOES matter.

Auber is 46.50 + $8 shipping to me....
I paid $20 with free shipping for my td4s but there are multiple sellers here in the States as well as overseas selling them for $26 including free shipping... so yeah the aubrins is slightly over double the price... you brought this up in another thread and I showed you the links already why do you refuse to believe it?
If your using an apple device to shop your prices may be showing up a bit higher but not as much as you quoted.
If the model matters that's good to know now but the point is the Op didn't know this and stated this. one would this the same settings would have the same meaning since pid logic is pid logic...

 

[BitterSipper]

one would this the same settings would have the same meaning since pid logic is pid logic...

Well the actual values can change model to model, or be inverse of each other. That's why I pointed out I wasn't asking about specifics but just general PID logic.

 

[Gameface]

Auber is 46.50 + $8 shipping to me....
I paid $20 with free shipping for my td4s but there are multiple sellers here in the States as well as overseas selling them for $26 including free shipping... so yeah the aubrins is slightly over double the price... you brought this up in another thread and I showed you the links already why do you refuse to believe it?
If your using an apple device to shop your prices may be showing up a bit higher but not as much as you quoted.
If the model matters that's good to know now but the point is the Op didn't know this and stated this. one would this the same settings would have the same meaning since pid logic is pid logic...

Because you're exaggerating how much more the auber stuff is. You did it in the other thread and you're doing it here. Just as much as pj seems to have a pro auber bias you seem to have an anti auber bias

 

[augiedoggy]

Because you're exaggerating how much more the auber stuff is. You did it in the other thread and you're doing it here. Just as much as pj seems to have a pro auber bias you seem to have an anti auber bias

How am I exaggerating it? I said they are twice the price. You stated yourself they want 46.50 plus shipping? can you add? 46.50 + $8 shipping (to NY for me) is $54.50... THIS
http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=3

IS MORE THAN TWICE THE PRICE OF THIS
http://www.ebay.com/itm/Universal-T...748?pt=LH_DefaultDomain_0&hash=item43bfdf893c

or this
http://www.ebay.com/itm/Universal-D...621?pt=LH_DefaultDomain_0&hash=item20d8476745


I dont know if your slow or what in case you are 26 x 2 is 52... which means you can buy 2 td4 mypins and still have $2.50 more left over than if you bought 1 auber unit....

recap again,
$54.50= 1 aubrins pid
$52.00 + 2 mypiun TD4 pids

I posted links that directly compared every single item from auber to the same exact parts from the same manufactuers linked elsewhere from other distributers in that thread SO I DID NOT EXAGGERATE ANYTHING!
Wow talk about living in denial!

I stated facts when I posted links to the mager ssrs that cost less (with a free heatsink!) than half what auber charges for the same ssrs they buy from mager and have rebranded.... anyone can easily see from the pics that they are the same considering they are the same label besides the name brand and even use magers model number...
I think people should know the facts especially when they come on here and mock others from buying overseas when they bought the same stuff for 35-100% more money from an American middleman I pointed it out to you in the other thread because you about to spend an extra $100 or more on your purchase from aubrins for the same exact stuff except the pids since auber pids are made in china exclusively for aubrins. all their sensors switches indicators and relays are just the same generic stuff marked up.

I stated 2-3 times the price in the other thread because the TD4 pid used to be available for $20 with free shipping but went up. (3x20 is $60) so depending on where you live and what auber charges you for shipping it would have been damn close to 3 times the cost and possibly more.. Since its been brought to my attention I have only stated they are twice the price and thats all I ever stated here in this thread. here is a cut and pate of the auction I bought to show what they cost in october...

 

[Gameface]

How am I exaggerating it? I said they are twice the price. You stated yourself they want 46.50 plus shipping? can you add? 46.50 + $8 shipping (to NY for me) is $54.50... THIS
http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=3

IS MORE THAN TWICE THE PRICE OF THIS
http://www.ebay.com/itm/Universal-T...748?pt=LH_DefaultDomain_0&hash=item43bfdf893c

or this
http://www.ebay.com/itm/Universal-D...621?pt=LH_DefaultDomain_0&hash=item20d8476745


I dont know if your slow or what in case you are 26 x 2 is 52... which means you can buy 2 td4 mypins and still have $2.50 more left over than if you bought 1 auber unit....

recap again,
$54.50= 1 aubrins pid
$52.00 + 2 mypiun TD4 pids

I posted links that directly compared every single item from auber to the same exact parts from the same manufactuers linked elsewhere from other distributers in that thread SO I DID NOT EXAGGERATE ANYTHING!
Wow talk about living in denial!

I stated facts when I posted links to the mager ssrs that cost less (with a free heatsink!) than half what auber charges for the same ssrs they buy from mager and have rebranded.... anyone can easily see from the pics that they are the same considering they are the same label besides the name brand and even use magers model number...
I think people should know the facts especially when they come on here and mock others from buying overseas when they bought the same stuff for 35-100% more money from an American middleman I pointed it out to you in the other thread because you about to spend an extra $100 or more on your purchase from aubrins for the same exact stuff except the pids since auber pids are made in china exclusively for aubrins. all their sensors switches indicators and relays are just the same generic stuff marked up.

I stated 2-3 times the price in the other thread because the TD4 pid used to be available for $20 with free shipping but went up. (3x20 is $60) so depending on where you live and what auber charges you for shipping it would have been damn close to 3 times the cost and possibly more.. Since its been brought to my attention I have only stated they are twice the price and thats all I ever stated here in this thread. here is a cut and pate of the auction I bought to show what they cost in october...

I'm glad you're a good bargain hunter. You should be very proud of yourself.

I'm not so slow that I don't know the difference between 2x and 3x as much, as you insist on repeating, even though you can't get to 3x the price even when you are manipulating the data.

The Auber PID costs $46.50

Shipping costs are for shipping. Good for you if you got it for free. When I have searched for MYPINS I did not find the prices you did.

I don't like ebay. So there. I don't want to have to buy every part from a different unknown vendor. I'm willing to pay more to not have to do that.

You take a tremendous amount of pride in paying as little as you possibly can fr things. I don't share your passion in that regard.

Despite our differences I think we can still be friends...so long as you refrain from personal insults like calling me slow.

 

[augiedoggy]

Shipping cost are a cost when I've repeatedly stated that we are comparing $26 including shipping to 46.50 + additional shipping costs...
Do you think the people selling the my pins don't have to pay shipping ?
Who is manipulating things now? Cost is cost no matter how you want to break it down I only said 2 times the price here.... Where in this thread did I say 3 x the price? I also explained why I USED to say 2-3 times the price because that was once the case...
If you don't like eBay that's fine but it doesn't make it any worse of a place because of it.. I have been using it since 2000 and have over a thousand purchases with only 2 bad experiences and both times PayPal refunded me.. most sellers are actually more than accommodating and for things like a paid if I fry it I wouldn't try to return it for a refund anyway since the would be dishonest.. and as far as the other stuff like SSRs switches, relays Senors and indicator lights well they either work or they don't? They are not complicated enough to need support.. if they are bad I contact the seller and they promptly send a replacement... its not like there's no support if you don't go through a middleman.. still that's your choice and I respect that. But it doesn't make what I have said any less true.
Honestly I was trying g to keep to the facts and be civil but I felt like I was I'm talking to a brick wall so I got a bit heated in my last response and for that I apologize. Its not that I take pride in paying as little as possible but rather I take pride in not overpaying for the exact same product from the same manufacturer when sold through middlemen ... especially when there is an untrue notion involved that the products from that vender are american and better because the middleman/ company is an american one .
I have no experience with the auber pods so they may somehow be better but the ones I have function perfectly for home brewing needs. And I dislike it when people come here looking for advice on what and where to buy and the same middlemen are always brought up and buying direct is shunned or frowned upon... If someone ison a tight budget it can make all the difference between making their system a reality or a Pipedream.

I also apologize for taking this thread further off course and for my poor spelling and punctuation since I'm using a smartphone.

 

[TungstenBeer]

I'm going to ignore the last page or so of posts and just comment on the topic, because this is something I've struggled with too with a Mypin ta4.

change the "I" to "1" leave all other settings at default and it will work fine and learns fairly quickly.... no need to autotune... I run 4 of these ta7 and TD4 mypins and they work just as well as the chinese auber pids sold at 2 -3 times the price despite the people making biased assumptions who likely did not have them setup correctly....

By chance, do you know what the default settings for P & D are? I've autotuned mine several times and a quick google search didn't turn up much of anything.

Speaking of autotune, here is how mine operates after numerous autotunings (the results are often the same, maybe with a half a degree difference or so). Let's say I set up my HLT to heat tap/ground water to 165F. It will work perfectly fine, probably until about 158-160F. At that point it will really slow down and take quite a long time to get up to 165F - maybe 20 minutes. Once it reaches 165F, it will continue to switch on and off until the temp settles 2-2.5 degrees higher, at 167F-167.5F. This isn't so bad to micromanage, but it sure is a nuisance I don't think I should have to deal with. Note: if I want to set the temp such that the PID stops switching my element on completely, I'd have to set it to like 162 or 163F, which I don't understand, but that's just some anecdotal information.

I apologize that I can't add what my settings are right now; I'll add them later when I'm at home and can verify. I am hoping this post will lead someone to say "yep, that's a problem that setting I=1 should fix," heh.

 

[Gameface]

*

 

[BitterSipper]

I'm going to ignore the last page or so of posts and just comment on the topic, because this is something I've struggled with too with a Mypin ta4.



By chance, do you know what the default settings for P & D are? I've autotuned mine several times and a quick google search didn't turn up much of anything.

Speaking of autotune, here is how mine operates after numerous autotunings (the results are often the same, maybe with a half a degree difference or so). Let's say I set up my HLT to heat tap/ground water to 165F. It will work perfectly fine, probably until about 158-160F. At that point it will really slow down and take quite a long time to get up to 165F - maybe 20 minutes. Once it reaches 165F, it will continue to switch on and off until the temp settles 2-2.5 degrees higher, at 167F-167.5F. This isn't so bad to micromanage, but it sure is a nuisance I don't think I should have to deal with. Note: if I want to set the temp such that the PID stops switching my element on completely, I'd have to set it to like 162 or 163F, which I don't understand, but that's just some anecdotal information.

I apologize that I can't add what my settings are right now; I'll add them later when I'm at home and can verify. I am hoping this post will lead someone to say "yep, that's a problem that setting I=1 should fix," heh.

Default settings are 3 for p and 240 for I, what you describe sounds fairly correct with p and I on. The point of PID is to get up to the temp quickly, without way overshooting, and then come down stabilized, if it just cut it off completely it thinks it would dip, so it's trying to softly bring it down. But it hasn't come up with values quick enough for you. If you want it to reach temp quicker you need "less" P (smaller number), but then you may overshoot more.

 

[TungstenBeer]

Default settings are 3 for p and 240 for I, what you describe sounds fairly correct with p and I on. The point of PID is to get up to the temp quickly, without way overshooting, and then come down stabilized, if it just cut it off completely it thinks it would dip, so it's trying to softly bring it down. But it hasn't come up with values quick enough for you. If you want it to reach temp quicker you need "less" P (smaller number), but then you may overshoot more.

How about D?

That makes sense. The thing is, it doesn't get up to temp that quickly (it gets up to temp minus 5 degrees or so quickly, but then it really slows), and it also never "softly brings it down," to use your words. At least not in the course of a 75 minute mash.

 

[BitterSipper]

How about D?

That makes sense. The thing is, it doesn't get up to temp that quickly (it gets up to temp minus 5 degrees or so quickly, but then it really slows), and it also never "softly brings it down," to use your words. At least not in the course of a 75 minute mash.

It's supposed to slow when it's that close to full temp. Try turning off all three P I and D and see what happens. That is straight on off, that will give you an idea of why it's supposed to slow as it gets closer. Just leave D off.

Mine never goes down either, even with only P on and no I, that has been my issue with this controller, it does not process like it should.

 

[TungstenBeer]

It's supposed to slow when it's that close to full temp. Try turning off all three P I and D and see what happens. That is straight on off, that will give you an idea of why it's supposed to slow as it gets closer.

I fully understand why it is supposed to slow down. I can't imagine it needs a full 10-20 minutes to make sure it doesn't overshoot though.

Just leave D off.

Roger.

Mine never goes down either, even with only P on and no I, that has been my issue with this controller, it does not process like it should.

Putting price completely aside, I guess this the overwhelming reason I want to move to Auber units. I've heard a ton of success stories using their units, and much more mixed reviews about anything else.

 

[augiedoggy]

Putting price completely aside, I guess this the overwhelming reason I want to move to Auber units. I've heard a ton of success stories using their units, and much more mixed reviews about anything else.

This is because of the amount of people using the aubers here vs other products, plus auber does have much better support to walk their customers who lets face it often know nothing about pids through every step to get them working correctly for this type of use. When someone pays good money they pay more attention to detail and are also more likely to follow through instead of just blaming it on cheap equipment and buying more expensive replacements when they get frustrated like often happens with cheaper stuff only to find it was something else they did or wired wrong... If I had a nickel for every time someone here replaced a mypin or even rex unit with an auber just to learn their temp probe or ssr was wired wrong..

Mypins support is horrible. But the pids do work well. I just took brumateurs advice when I had the overshooting issue and set the i setting to 1 and it completely resolved my problems.. I have no temp spikes or dips more than a degree or two which last for a few seconds before the pid adjusts .. nothing that would have any actual effect on the brewing process.
There are plenty of auber pid issue threads like the one I linked earlier...

and you will see a lot of people warn others here not to buy the "cheap ebay pt 100 probes" and recommend auber instead even though they come from the same manufacturer and work exactly the same... same with these ssrs being recommended.
http://www.auberins.com/index.php?main_page=product_info&cPath=2_30&products_id=30

instead of these which are from the same manufacturer and come with a heat sink for almost half the price!( Very likely less than half with shipping )
http://www.ebay.com/itm/New-Solid-S...455?pt=LH_DefaultDomain_0&hash=item417e80a597

http://www.ebay.com/itm/New-Solid-S...064?pt=LH_DefaultDomain_0&hash=item35cbbd7228

Bottom line price changes perception... if someone gets it cheap they are more likely to not put as much care into wiring it up right in my opinion.. this can effect somethings reputation...

BTW I see your in buffalo... your more than welcome to check out my TD4 pid setup and see how it /they work if you like?

 

[TungstenBeer]

This is because of the amount of people using the aubers here vs other products, plus auber does have much better support to walk their customers who lets face it often know nothing about pids through every step to get them working correctly for this type of use. When someone pays good money they pay more attention to detail and are also more likely to follow through instead of just blaming it on cheap equipment and buying more expensive replacements when they get frustrated like often happens with cheaper stuff only to find it was something else they did or wired wrong... If I had a nickel for every time someone here replaced a mypin or even rex unit with an auber just to learn their temp probe or ssr was wired wrong..

Mypins support is horrible. But the pids do work well. I just took brumateurs advice when I had the overshooting issue and set the i setting to 1 and it completely resolved my problems.. I have no temp spikes or dips more than a degree or two which last for a few seconds before the pid adjusts .. nothing that would have any actual effect on the brewing process.
There are plenty of auber pid issue threads like the one I linked earlier...

Bottom line price changes perception...

I cut some stuff out that I didn't find relevant. SSRs, temp probes - I agree with you on those, they function the same no matter how much money you spend. It's like buying a $1000 alarm clock... just silly.

In my case, I've used a Mypin TA4 for over a year in a HERMS setup (boil with propane) and I've never been able to set it correctly. A very close friend of mine has had the exact same issue with the same oscillations. After all this time, I may have found a workaround that I have yet to try (setting I=1) but have really only seen posted by you on this forum. It isn't mentioned in the manual, and it's not a common enough product (compared to a TV or car or something) to where there is an absolute abundance of resources online. In my mind that makes for a really poor product; the unit doesn't work as it should, the instructions don't help, and the one or two things that might help are from users that happened to figure it out.

In the meantime I've been able to brew around my issue with relative ease, but it required quite a bit of monitoring and a handful of manual adjustments every mash just to get a stable temperature. THAT alone would be worth an extra $20 or $30 or more just to not have to deal with that headache.

The few brewers I've gotten to know that have gone electric based off Kal's design haven't used MyPins and haven't had these issues. Granted, the sample size of people I'm talking about is very small but it seems very validated by what I see on these forums and on others.

On a somewhat unrelated note - I wonder how much the "fuzzy logic" that some units use have to do with the perceived success rates. I've tried reading up on it; but since I feel like I have a rudimentary understanding ONLY of how a normal PID functions, I certainly can't decipher any of the limited resources I see on the web.

 

[BitterSipper]

Mypins support is horrible. But the pids do work well. I just took brumateurs advice when I had the overshooting issue and set the i setting to 1 and it completely resolved my problems.. I have no temp spikes or dips more than a degree or two which last for a few seconds before the pid adjusts .. nothing that would have any actual effect on the brewing process.
There are plenty of auber pid issue threads like the one I linked earlier...

Could you do an experiment for me. I assume you are heating mash water or heating a HLT? Starting from at least 20 degrees cooler than your set temp start your unit up. Press the "set" button so it displays output. What is it ~10 degrees from your set temp, 5 degrees, at, and above it? Repeat after turning I off (but write it down so you can change it back). I'm very curious if your controller is still outputting like mine, but your dissipation and volume is high enough that it doesn't factor.

 

[schematix]

Can these PIDs run in a thermostat mode? Wondering if anyone has had success holding +/-1F just using that...

I did want to make a few other comments on PIDs though based on some of the things i've read here that are incorrect:

1. P - the more aggressive the gain, the quicker you reach the set point, but more you will overshoot. The effort the controller applies is proportional to the difference between the set temp and the actual temp. For some controllers this is 1/Kp, and for some its Kp. Just know if increasing the value increases the aggressiveness, or lowers it. If you're overshooting, turn your I down low or off, then see how you're overshooting.

2. I - This is the portion of the controller that "learns" the system over time based on the history of the error. A more aggressive I-gain leads to more overshoot (it has to accumulate negative error to counteract the positive error when it was below the set point), but better long term steady state tracking. It sums the error (set - actual) over time, and weights it with the I-gain. Again, depending upon the form of the PID the controller uses, increasing the number can either increase of decrease the aggressiveness.

3. D - This portion of the controller attempts to slow the rate of change. Just turn it off. Sometimes its helpful, but usually its not. PI controllers are the way to go for 99% of applications.

4. Temperature systems are inherently slow, which leads to problems for pure PIDs. The purpose of a controller is control an output to match an input. However, the nature of the input has a huge impact on the controller and the output. In general, a tight controller is needed to hold a system at a set value (this is called disturbance rejection). However, a controller that is changing inputs (called set point tracking; ramping from 145F to 158F to 170F) needs a "soft" controller to prevent overshoot. This is made even worse by the inherent slowness. There are many solutions to this problem. The better solutions use dynamic gains and consider the systems rate of change. Some simple solutions like Auber's "fuzzy logic", uses a different control technique when its close to its set point to prevent the dreaded overshoot associated with set point ramping and the integrator winding up.

This thread is clearly user error. This stuff isn't simple, but its not rocket science either.

 

[augiedoggy]

Keep in mind I use one for control of my rims tube as well so if it overshot that would be a big deal....
I wish I could post videos to show how its working (which is why I offered Tungsten the opportunity to check mine out in person if he wanted since I'm 10 minutes from buffalo...)

in any case I still recommend someone change the i setting to 1 and try it...