This question is relevant to the 'search' function capability.
After reading this post, which took a while, I've decided to ask a question, which is a SLC 5/04 PID question. I've never asked it before, as I figured it would not get answers, as many would consider it 'just another PID question without research'.
As far as the topic of search function, most of the answers I've ever needed, I had seen here in the past. If there was a way that I could save post here on the site, that would be awesome. But some times there are specific questions, about common topics, such as PID's, which are best solved by posting. Take care to not pass by a post, just because it is a common topic.
Here is the PID question. I apologize that I cannot post the code:
The PID is controlling speed, to maintain steady web tension.
After a ton of research, every thing I read said to put my I and D gains to 0.0, and adjust P gain, until oscillation, and set it at half of that value. The problem is, when I put the I to 0.0, and did a bumpless transfer, with my CV at 27%, from manual to auto, my CV dropped to 0% immediately, and then responded. In that time, it made one hell of a mess.
My bumpless transfer works now, and the PID controls, as by just educatedly guessing, I came up with P=5, I=.05, D=0.0.
My question #1 is, I believe with the 5/04, I is faster the lower the number, so for this test to find gains, I should've had a high number in the I gain?
My question #2 is, even with an I gain of 0.0, if my setpoint is equal to my process variable, why does the control variable drop to 0%, and then try to respond, when I switch from manual to auto?
Like I said, sometimes there are specific questions, to common topics, which require a post.
Update: Actually ended up with a P =.2, I =.1, D = 0, which gives good response, with no overshoot. The gains shown are with the RG not set. With the RG bit set, it would be by 2,1,0.
As I am on my own now, I only do automation work occasionally, and have no one I can go to with questions. This site is my 'go to' person. Without it, I could never have made this project work.
Thanks to all!
After reading this post, which took a while, I've decided to ask a question, which is a SLC 5/04 PID question. I've never asked it before, as I figured it would not get answers, as many would consider it 'just another PID question without research'.
As far as the topic of search function, most of the answers I've ever needed, I had seen here in the past. If there was a way that I could save post here on the site, that would be awesome. But some times there are specific questions, about common topics, such as PID's, which are best solved by posting. Take care to not pass by a post, just because it is a common topic.
Here is the PID question. I apologize that I cannot post the code:
The PID is controlling speed, to maintain steady web tension.
After a ton of research, every thing I read said to put my I and D gains to 0.0, and adjust P gain, until oscillation, and set it at half of that value. The problem is, when I put the I to 0.0, and did a bumpless transfer, with my CV at 27%, from manual to auto, my CV dropped to 0% immediately, and then responded. In that time, it made one hell of a mess.
My bumpless transfer works now, and the PID controls, as by just educatedly guessing, I came up with P=5, I=.05, D=0.0.
My question #1 is, I believe with the 5/04, I is faster the lower the number, so for this test to find gains, I should've had a high number in the I gain?
My question #2 is, even with an I gain of 0.0, if my setpoint is equal to my process variable, why does the control variable drop to 0%, and then try to respond, when I switch from manual to auto?
Like I said, sometimes there are specific questions, to common topics, which require a post.
Update: Actually ended up with a P =.2, I =.1, D = 0, which gives good response, with no overshoot. The gains shown are with the RG not set. With the RG bit set, it would be by 2,1,0.
As I am on my own now, I only do automation work occasionally, and have no one I can go to with questions. This site is my 'go to' person. Without it, I could never have made this project work.
Thanks to all!