williamlove
Member
I am using a CompactLogix with a 1769-IF4 card for a pressure control loop. I want to achieve tight control.
Let’s leave loop update time and scan rate out of this . . . I know how to use those and I know how to set them when I have specified how often the PV will be updated.
My question is regarding how often I should update the PV based on the response time of the pressure sensor, e.g. 250millsec. I am hoping someone will explain how you use the sensor response time to determine—in a precise way—how fast I should update the PV using the available settings of the analog input card.
It would be very helpful if you would explain if it is possible to update the PV too frequently, and if so, why?
Let’s leave loop update time and scan rate out of this . . . I know how to use those and I know how to set them when I have specified how often the PV will be updated.
My question is regarding how often I should update the PV based on the response time of the pressure sensor, e.g. 250millsec. I am hoping someone will explain how you use the sensor response time to determine—in a precise way—how fast I should update the PV using the available settings of the analog input card.
It would be very helpful if you would explain if it is possible to update the PV too frequently, and if so, why?
