Created Date: May 09,2014

Created by: Tinker

Any ideas what can be done becasue at present the ramp feature is more or less useless since the set temperature must be reached before the soak starts or the heat treatment process will fail?

Not that I actually have any real information, but my guess is the ramp feature was driven more by marketing than engineering. Considering the price of a SOLO, and how cumbersome programing a ramp/soak is I suspect it is there just so they can say they have it but they don't really expect it to be used much and as such, I suspect testing was not as rigorous as might be done for say, a $400 controller.

I too was considering using a SOLO on a heat treat oven, and to deal with the programing complications I was going to use a C-More, but after considering the fact that with a C-More this wasn't a low budget project, and the fact that the SOLO doesn't have way to postpone the soak until the target temperature has actually been reached I decided I'd be better off just using a PLC rather than a SOLO. (this is still a hypothetical project, I haven't done it yet)

BTW, if I do do this, it will be an Automation direct PLC and C-More, and I have used a fair number of SOLOs for basic control, so I'm not really putting down the SOLO/ Automation Direct/Koyo , I'm just saying you get what you pay for. Also I strongly suspect ADC just has the SOLO privately labeled for them by a company they have little control over (consider the lack of action on the frequent complaints about screen size and SoloSoft)

Created Date: May 09,2014

Created by: brad72

I 've never used this specific controller, but looking at the manual, it appears that this controller supports multiple PID parameter groups. It looks like you can select which PID parameter group to use in the configuration software. Is it possible that your ramp-soak profile is using a different parameter group than a manual adjustment?

Thanks for the response. I have tried selecting the exact pid profile, a profile for a higher temp and setting to auto which chooses the closest save profile but the result is still the same.

Created Date: May 09,2014

Created by: brad72

Not that I actually have any real information, but my guess is the ramp feature was driven more by marketing than engineering. )

I was wondering this and as you said the fact that the soak is not postponed till the set point is reached is a bit anoying as the soak at a given temperature is crucial.

I might try another couple of things as see what happens. As a basic controller I cannot fault it and its accuracy is second to none, just the ramp portion is flawed.

Created Date: May 11,2014

Created by: brad72

So I did a few more tests over the weekend. Remember the oven can get to 800ºc in about 55 minutes in manual mode.

1. reset the controller to factory defaults then re-ran the auto tune pid groups of 800 and 1037ºc.

2. set a ramp temp of 800ºc and time of 90 minutes with a soak of 10 minutes and chose the 800ºc pid group

The result of this was the controller still rampted up to slowly only getting to 785ºc before the soak started and then took another 5 minutes to get to the actual temperatuer of 800ºc

So, simple I thought, I will add another 10 minutes to the ramp time to give it time to reach the set temp so I ran another cycle with a 100 minute ramp but again the controller fell short by 17ºc this time before the soak started.

Conclusion is that the controllers ramp/soak is useless for my application unless there is some setting that can be tweaked to make it ramp up a little faster, however there is nothing mentioned like this in the manuals. Otherwise i guess I will have to run each ramp soak program to see how many minutes it takes to reach the set temp then adjust the soak to suit. Since I have about 10 different cycles though no a quick task.

Unfortunatelty also my local supplier has no experience with these controllers so can give me no advice.

Created Date: May 09,2014

Created by: brad72

Hi Guys

I have recently build a heat treat oven and am having issues with the ramp/soak feature. I have set my 3 PID groups, being 800, 850 and 1037ºc and the controller will get upto and keep within 1º of the set point when PID program is selected. The issue comes when I set it to ramp soak.

Currently I have set a ramp pattern 0 with a 90 minutes ramp with a target temp of 800ºc, then a soak for 10 minutes. I know that to get from ambient to 800ºc take 60 minutes in manual mode so the 90 minute ramp gives plenty of time. I have also set the PID group to match the closest of the ones I auto tuned. The issue is that the controller only pulses output 1 at about 40% and then slowly creeps to about 80% meaning that it never reaches the set point before the soak cycle begins. With 90 minute ramp the controller fell short by about 20ºc

For a test tonight I set the ramp to 60 minutes with a target again of 800ºc and it only reached 600ºc before the soak started. It seems that the algorithm is wrong with the controller starting the heating cycle too late and then does not give enough power to output 1, only slowly pulsing the output when it should be on 100%. Even with 15 minutes left and needing to rise 300ºc the output is still only pulsed at about 50%.

Any ideas what can be done becasue at present the ramp feature is more or less useless since the set temperature must be reached before the soak starts or the heat treatment process will fail?

Cheers