adccommunitymod (AutomationDirect) asked a question.
Created Date: November 30,2007
Created By: gmarshall
**** This post has been imported from our legacy forum. Information in this post may be outdated and links contained in the post may no longer work.****
I have a DL-05 and a F0-04THM 4 Chan. but using only 1 channel. I am heating up water to 95 C. When I have the PID values set for a high flow it works great. Then I change the water flow to low flow I also reload the PID values that are correct for low flow. When I start heating the water the Control Output Value is high as was needed for the high flow. When I change the PID values I also change the Setpoint to zero until I turn on the heater when I set the Setpoint to 95 C. If I cycle the power to the PLC it works great but I do not want the user to be required to cycle the power whenever they change the flow and PID values. How can I reset the PID auto controler to forget the previous heater values that it used for the Control Output Value and Bias Value? The controller thinks it is still doing high flow and does not use the new PID values that were loaded into the PID controller.
Created Date: December 01,2007
Created by: MacS
http://web1.automationdirect.com/static/manuals/d0user/ch8.pdf
See note at bottom of 8-22
Created Date: December 03,2007
Created by: gmarshall
Okay. I can change the PID loop to manual mode before changing the PID values, but you can not stop the PLC. The manual says that I must use the programming device such as DirectSoft32 to do these changes. The customer does not have DirectSoft32 or DirectSoft5 connected to the PLC. I have the AutomationDirect C-more Micro-graphic 3 " non-touch panel controlling the PLC. All of the real control logic is in the PLC that must be running when making PID value changes. Therefore, I can NOT have the PLC be in stop mode when making PID value changes from the display panel.
Created Date: December 05,2007
Created by: hanziou
All you have to do is to output the different parameters into the appropriate locations on 'flow rate change '.
E.g. if the PID table starts at V2000, just load your new bias value and then OUT to V2004.
If you have different tuning coefficients for the high flow versus low flow you can LD the gain, Reset and Rate values on rate change.
There a few of the parameters that can not be changed "On the fly ". (Check out the table on 8-20 of http://web1.automationdirect.com/static/manuals/d006userm/ch8.pdf to see which of the parameters can be changed "on the fly " )
Created Date: December 05,2007
Created by: gmarshall
Thanks for the information about what PID parameters that can change on the fly. I do not have the DL-06 but I assume it will apply to the DL-05 PLC. They need to update the DL-05 to show what can change on the fly. I am able to change the main PID variables on the fly.
Thanks again for all of your help.
Created Date: November 30,2007
Created by: gmarshall
I have a DL-05 and a F0-04THM 4 Chan. but using only 1 channel. I am heating up water to 95 C. When I have the PID values set for a high flow it works great. Then I change the water flow to low flow I also reload the PID values that are correct for low flow. When I start heating the water the Control Output Value is high as was needed for the high flow. When I change the PID values I also change the Setpoint to zero until I turn on the heater when I set the Setpoint to 95 C. If I cycle the power to the PLC it works great but I do not want the user to be required to cycle the power whenever they change the flow and PID values. How can I reset the PID auto controler to forget the previous heater values that it used for the Control Output Value and Bias Value? The controller thinks it is still doing high flow and does not use the new PID values that were loaded into the PID controller.