PROGRAMMING a Golander GL1101 Intelligent Temperature Controller (PID)

[dragon813gt]

also, i don't want to see the PID running in 2 seconds cycles all the time. i'd rather have the PID working till the temp asked is reached,then switching to off till the temp fall down like 20 degrees .

Then you don’t want a PID. For a twenty degree swing a simple bimetal thermostat will work. That’s what’s in the pots to begin w/. I read the instructions and the OT setting is a stupid one. It defeats the purpose of the PID if you’re going to set a cycle time. In real PID loops the time function is how often it looks at the values and makes corrections to the control value.

[Mike W1]

Then you don’t want a PID. For a twenty degree swing a simple bimetal thermostat will work. That’s what’s in the pots to begin w/. I read the instructions and the OT setting is a stupid one. It defeats the purpose of the PID if you’re going to set a cycle time. In real PID loops the time function is how often it looks at the values and makes corrections to the control value.

Agree with your thoughts above that are better expressed than I'd have been able to. I had a somewhat similar experience with a couple Mypins and rather than tear my hair out returned them and replaced with a couple Rex units that have worked just fine.

[glockfan]

sorry, i was simply exposing my concept of a PID and how it seemed to work from my little knowleadge about it .

i see it in it's simpliest expression : i'm asking 725 degree to the pid,and the pid heat the pot till it reach the temp i've asked.once the temp reached ,pid stop to heat...and so on in short cycles ,at least it was my comprehension of the process .

[dragon813gt]

If it doesn’t shut off until it reaches setpoint it’s going to overshoot. W/ a cold pot the control value, CV, is going to be 100% so it will always have the pot on. As the Process Value(PV), actual pot temp, gets close to the setpoint the CV starts backing off. This is when the PID starts turning the relay on and off. The closer the PV gets to setpoint the lower the CV. Realistically the CV should be very low but not zero. You can’t see how all of this is working like you can on a PLC w/ a HMI.

The goal is to have the pot settle in exactly on the setpoint. but it’s only going to be able to do this w/ the pot level you set it up at. There’s a massive difference in load between a full and three quarters empty pot. You can expect it to overshoot a lot at three quarters empty if you tuned it when full.

[40-82 hiker]

I would like to chime in with what I have done with my PID from Hatch, and what I now understand about it.

1) Auto tune worked just fine for me after a learning curve on my part. However, I did not understand what was going on at first, and had to turn off the PID a few times during auto tune and consult my computer via Google. The PID did NOT turn off the pot after climbing far above SV (the target temp) and cooling off way below SV-Hy (the Hy setting). I’m thinking it HAS to do this to populate the readings needed to figure out the Integral value (the total value of “errors” over time), and the Derivative (the slope of the Proportional curve). The Proportional value as well, of course.

2) I performed the auto tune as noted by others, in that I did not start it cold. I heated the lead directly (w/o the PID) to around 650*, then switched the cords around and turned on the PID. I set SV to 725* to start with, and left all other settings alone. After finally running the auto tune 3 times (I just let it cool back down to around 650 each time), I changed SV to 730 and let it run auto tune AGAIN a couple of times. THEN, I reset SV back to 725 and tested the stability of the PID at that temp. Over the course of ½ hour the temp never exceeded 726, and never went below 722 (just once), though almost all of the time it was at or above 723. I was dumfounded to say the least! For most of the ½ hour the temp was within a 4* window, with a Lee 4-20, and actually some of the time it just went back and forth between 725 and 726!

I have not cast with this PID yet. My back was only just now okay to finally use the PID, and I used it up in the time it took to get the PID up and running.

I will also note, that I find the oT setting to be a rather confusing aspect of this PID. At times it seems to be at odds with the logic of things. Greatly! However, I left the setting at “2”, and it seems to be just fine as such. I did try a few other settings, but it upset things rather than made it better. I realize this is at odds with others, but hey, it’s what I have, and I’ll live with it. There is still a great mystery about this to me, and what I do not know is quite awesome. So, ask me a few months from now and it is possible I will know no more than I do now, because if it works, I’m not going to do anymore figuring, just casting.

At this point I am pleased with this PID. Now, to casting with it...

[Mike W1]

Any time I've AT'd one of my units it's been turning on AT when I get within 20-30° of my SV and then let AT run it's cycles. I get the idea with a drop down to 650° you're manually turning the power off to the pot which I believe defeats the purpose of AT by for lack of better terminology is you're putting a low temp that isn't really part of the cycle. Can't imagine a 20 pound pot dropping quite that far down. At least none of mine have ever varied that far and I've done a few of them now.

[40-82 hiker]

Any time I've AT'd one of my units it's been turning on AT when I get within 20-30° of my SV and then let AT run it's cycles. I get the idea with a drop down to 650° you're manually turning the power off to the pot which I believe defeats the purpose of AT by for lack of better terminology is you're putting a low temp that isn't really part of the cycle. Can't imagine a 20 pound pot dropping quite that far down. At least none of mine have ever varied that far and I've done a few of them now.

Edit,

I did not understand your post correctly, so I deleted my initial response. Sorry about that. Not paying attention on my end here...

Okay, here goes:

You misunderstood what I posted. I ran the AT three times, letting it got through its complete AT cycles each time. Between each of the three times I ran the AT I let it cool down to 650 by turning the pot off, and then turning the PID back on and starting another AT cycle. I never did interrupt the AT cycle, I just waited for the PID to run the entire cycle.

Sorry again for the confusion on my part when reading your post.

[Mike W1]

Obviously it was I that was confused, not you! FWIW I've found that the parameters will change slightly every time you run the AT feature with the same setup and it probably doesn't really help but it doesn't hurt anything either. Wiser souls than I have said that, I'm just repeating what they told me.

[popper]

I don't understand the OT setting. It is the update rate of the calculations. It is a pulse width modulation system, on time is between 0 and 2 sec (for OT=2sec), as determined by the % on needed. Set long if a relay system so the contacts don't chatter.
AT mode basically turns the heater on til set temp and remembers the time/temp curve, adjusting parameters for a faster response. Basically looking for overshoot and reducing it.

[DukeInFlorida]

The OT settings, specifically, is basically how often the RELAY clicks in and out, applying voltage to the circuit. The default settings is 002. The relay is the only physical moving part. My manual setting is 005. So, my relay will cycle 2.5 times LESS than the factory setting. (Did I do the math correctly??? No matter, the point is that my relay cycles less than the factory setting). My thought process for OT was that by reducing the amount of times it cycles, it will last 2.5 times longer, which should at least be MY lifetime!! Hope that helps.

By the way, my settings were derived by consulting with my best friend, Kicker92FS, who lives in Massachusetts, and for the past 30+ years, has run the equipment side of two commercial bakeries. He is not only a master with PID's, but also with FULL LOGIC controllers. 90+ % of his factory machinery (making all sorts of bread - sandwich shops, restaurants, and retail stores) is PID and full logic controller operated. Kicker was instrumental in helping me understand the nature of these things.

I don't understand the OT setting. It is the update rate of the calculations. It is a pulse width modulation system, on time is between 0 and 2 sec (for OT=2sec), as determined by the % on needed. Set long if a relay system so the contacts don't chatter.
AT mode basically turns the heater on til set temp and remembers the time/temp curve, adjusting parameters for a faster response. Basically looking for overshoot and reducing it.

[popper]

Relays are spec'd by operating cycles or MTBF. Turn your filter ON (2) and set the OT to 7. The other problem is that you may burn the contacts due to short on time (arcing). You can increase the HY (dead band) value so the relay doesn't operate so often. I highly recommend a SS relay with good heat sink for anybody using a PID on a melter. Relays are like the point ignition system in your old car - they wear out. fast. If you cast just one hour, 5 sec. OT That is 750 closures, or 6 1/2 hrs of casting for a 5000 cycle rated relay. The other disadvantage is the relay may open at a high line voltage, more arcing. At the setpoint temp they may never turn on as the ON time is too short to operate. SS relays turn on & off at 60 hz rate always, with just a OT recalculate rate.

[glockfan]

i'm following this thread cuz i'm getting my PID in couple days( tracking say about to be delivered).

so,lets say i'm the kind of caster who cast for 3-4 hours sessions. would you leave the original settings as is,or would you adjust OT or any other settings differently,so you can make it easier on the PID?

i'm asking because i'd like to be able to lenghten the PID lifespan.

[popper]

PID is sort of a computer so it will last like any electronics. The SSR should have a large heat sink (and use heat sink compound when mounting) and be 2x current rated. Again, electronic so keep it cool and it will last as long as you do. The temp probe is the normal failure part - get a couple.

[glockfan]

PID is sort of a computer so it will last like any electronics. The SSR should have a large heat sink (and use heat sink compound when mounting) and be 2x current rated. Again, electronic so keep it cool and it will last as long as you do. The temp probe is the normal failure part - get a couple.

do you recommend keeping the PID settings as it comes ?

i've finally got it.i'm trying to figure a bracket for the probe.

someone posted in this thread that leaving the PID on AT for couple hours in a pot full of melt is the best way to let AT settles.

what do you think would be the best procedure to break in a brand new unit ?

[Mike W1]

AT (automatic) usually lets the hi/lows cycle 3 times then shuts off. Doing it more than that won't hurt but unlikely to help either. Turn it on when the temperature gets within about 20° of the SV. That's really all you normally have to do as most units come set from the factory for K type TC's. It really isn't a bad idea to go through the parameters and record them before you change anything though. Far as I know the only values AT will change are the P, I, & D values. And those will be the ones that'll work with the particular item (lead pot, hot plate, etc.) If you switch units you'd need to AT it. Again record those values for future use so you can manually input them and not have to go through the AT process again.

[DukeInFlorida]

Silly me didn't even try the standard settings that came with the controller. I saw the AT option, and jumped right on that. MISTAKE in my humble opinion.
My only seeming way to undo the errors that the AT introduced was to do the manual settings I indicated earlier. My controller now works perfectly for me.

BTW, I found another interesting use for my controller. I, and a group of buddies, make a bullet lube, which is a modern version of an old lube whish was called Best Lube. The original maker kept the recipe and process a closely guarded secret, and took that to his death. A once young employee, now here as GunArea (Roy Kramer, the originator of the Lawn Steel Game, otherwise known as ILSA) took some lube samples to a research chemist, and came up with the replacement recipe. He's given permission to post it publicly. BEST LUBE RECIPE. That recipe requires a heat source, and varying heat stops along the way (for polymerizing the molecules.). During the last session, last Saturday, we used the PID for controlling the heat source (hot plate) and measured the temperature of the lube along the way. Best batches we ever made!!

do you recommend keeping the PID settings as it comes ?

i've finally got it.i'm trying to figure a bracket for the probe.

someone posted in this thread that leaving the PID on AT for couple hours in a pot full of melt is the best way to let AT settles.

what do you think would be the best procedure to break in a brand new unit ?