adccommunitymod (AutomationDirect) asked a question.
Created Date: January 06,2016
Created By: paulreeder
**** 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 Information in this post may be outdated and links contained in the post may no longer work.****
Hello All- At our food plant, we often use Open Loop Temperature control (No temperature feedback). In the past, we used mechanical Eagle Signal & ATC "Percentage Timers ", where, with a fixed time period (30 seconds worked for us), the output could be set to turn on a percentage of the 30 seconds. Set at 50%, the output would be on for 15 seconds & off 15 seconds. Set at 10%, the output would be on for 3 seconds and off 27 seconds. Being mechanical, the % timer life span was about 3 years. Even solid state ATC brand timers would also not last very long. I found nothing for open loop control in the manual or from Tech Support, So I experimented and was able to easily adjust it for open loop control. Take any of the SOLO controllers (Size doesn't matter!) and set as follows: Setup Parameters - PCd0 = 0 Su0 - 0 P0 = 10.0 C0 = 0 d0 = 0 PdoF = 0 HtPd = 10 (Adjust as needed, it's the Time Period, in seconds) tPoF= -4 (Again, adjust as needed to show a PV of 0) Initial Setting Parameters - CnPt = u10 tP-H = 100 tP-L = 0 CtrL = Pcd S-HC = Heat I have only used this for SSR fired heating outputs (SLXXXX-VR), so my time period can be short. Obviously, triggering contactors or other outputs may not be suitable. Good Luck. "May the Control be in your Favor " Ha Ha -Paul Reeder
Created Date: January 06,2016
Created by: paulreeder
Sorry, but I forgot to add the operation mode. Simply set the SV for 0 (0% output) on up to 100 (100% output), or anything in between.
-Paul Reeder
Created Date: January 06,2016
Created by: paulreeder
Hello All-
At our food plant, we often use Open Loop Temperature control (No temperature feedback). In the past, we used mechanical Eagle Signal & ATC "Percentage Timers ", where, with a fixed time period (30 seconds worked for us), the output could be set to turn on a percentage of the 30 seconds. Set at 50%, the output would be on for 15 seconds & off 15 seconds. Set at 10%, the output would be on for 3 seconds and off 27 seconds.
Being mechanical, the % timer life span was about 3 years. Even solid state ATC brand timers would also not last very long.
I found nothing for open loop control in the manual or from Tech Support, So I experimented and was able to easily adjust it for open loop control.
Take any of the SOLO controllers (Size doesn't matter!) and set as follows:
Setup Parameters - PCd0 = 0 Su0 - 0 P0 = 10.0 C0 = 0 d0 = 0
PdoF = 0 HtPd = 10 (Adjust as needed, it's the Time Period, in seconds)
tPoF= -4 (Again, adjust as needed to show a PV of 0)
Initial Setting Parameters - CnPt = u10 tP-H = 100 tP-L = 0
CtrL = Pcd S-HC = Heat
I have only used this for SSR fired heating outputs (SLXXXX-VR), so my time period can be short. Obviously, triggering contactors or other outputs may not be suitable.
Good Luck.
"May the Control be in your Favor " Ha Ha
-Paul Reeder