06-13-2011 07:40 AM
My application consist in a NI USB-8486 convertor connected to a Biffi Fieldbus Valve with integrated PID (FF 2000 v4 ,revision 2). I'm using NI FBUS Configurator software from National Instrumens to create a test project for PID control. For the phisical bus connection i'm using some Phoenix Contact connectors with cables and power supply for the bus. I succeeded to download a simple configuration in Biffi and to force some Open/Close commands through the DO Block but i cann't make any movement using the PID. I tried to use the PID Feedback Control template replaceing the coresponding blocks (follwing the manual instructions) and no succes!! In monitoring all the configured blocks are in the correct Block_Mode, I can see that the pid algorithm is reacting when i change the setpoint from a second AI block(in Manual mode) that i use for this purpose, the Transducer block seems to display correct information - regarding the Setpoint_Read, Position, and the Command_Read:"Enable setpoint"( I'm not sure if this is the correct active command for this parameter) and still ...the movement is not triggered.
I attached also the project, maybe you can give me a hint about this.
Thanks!
06-14-2011 12:22 AM - edited 06-14-2011 12:23 AM
I noticed that the "CAS_IN" parameter in your PID block is in "Good_NonCascade" status. Could you try to configure it to the "Good_Cascade" status through changing some PID options?
06-14-2011 04:09 AM
I'm working for the firs time with Fieldbus, and frankly...i have no ideea witch parameter should i change in PID block besides the Scaling parameters witch seems to be correct. But, as you can see in the attached image, the feedback Position apears with Status_Quality:Good_NonCascade in the TransducerBlock1, also in the AI block and I don't understand why, ...as long the value of the current position is exactly as that one displayed on the Biffi valve. I tried to change some parameters anyway...but no success 😞