AB Micro 1200 analog input ?

[jseavers]

Hi, I ran into a problem on a project and was hoping for some insite. What I have is a micrologix 1200 ser. C PLC with a 1762-IF4 analog input card reading a 0-10 volt analog input from a Turck EZ Track Q21R position transducer. The position tranducer is on a hydraulic press measuring a stroke that is 10 inches long. The position is right on as long as the press is not moving but when I move the press ram the position lags or seems to update slow and the press will overshoot. I'am using the SCP function to scale the 0-32767 input to 0-10 inches. In the SCP function the scaled input is going to floating point and then compare instructions for starting and stopping of the ram. The cable length of the position sensor is about 7-8 feet so I do not think that it is the problem. Do I need to figure out a way to scan the SCP rung faster? Thanks for any feedback!

 

[CroCop]

Post a trend.

Post the raw feedback, the raw setpoint, the scaled feedback, the scaled setpoint, & your program.

How are you controlling the speed of the hydraulic cylinder?

 

[Mickey]

How slow is slow? Then take a look at your filter setting.( see pic)

 

[jseavers]

Thanks, Mickey I Changed the filter setting for the analog module and my overshooting of the ram came down. Its still not perfect but with in limits to run.

 

[agarb]

Can you anticipate the ending position and issue the stop command sooner? Can you do closed loop control in your PLC?

Or buy one of Peter's controllers.