Hello,
Just a brief request for advice. I have attached a plot with the four active 4-20 mA signals coming in to my RMC, and I would love your opinion on the loud noise I get on Cap and Rod signals (WOB channel A and B up and down by 0.07 mA at 62Hz).
I have IFM Efector PA3221 transducers installed. They cover a 0-3625PSI range and I am only supplying 500PSI so I do lose some resolution which makes matters worse.
How usual is this, how manageable, and what is the best way forward for filtering and tuning under these conditions?
Thanks
mA_Signal_Noise.rmcplots (420 KB)
60 Hz is difficult to filter out and still obtain good pressure control. I would check the wiring to make sure that the commons are connacted properly, that the wires are twisted pair and shielded, and that the loop is area is as small as possible. If the wires are spaced far apart, they become an antenna that will pick up noise. Make sure to follow the iwring diagrams in the RMC Startup Guide. Make sure to get a recent version of the startup guide, since we updarted some of the 4-20mA wiring diagrams to address these types of problems.
The RMC only has low-pass filters, and typically filtering below 60 Hz is not a good idea for presure, unless the system responds very slowly. What type of system do you have?