There are Integrated 2oo3 for PID control in DCS systems? How to prevent PID malfunctions due to instrument failure different to bad PV or step change fails?
Lately we have faced in my plant a few shoot downs due to instrument fails associated to PID controllers. I'm not talking about the SIS or Interlock system, The shoot downs has occurred after erroneous movements of the PID associated valves. That happened because the instrument didn't went to bad PV or showed a strong change in an step; instead of that, the instrument transmitted a smooth increasing or decreasing signal deviating itself from the real value. The DCS in my plant is a HONEYWELL TDC-3000. I already searched for an integrated 2oo3 PV regulatory and I didn't find it. So the idea that came to my mind was if there is this tool in other DCS, or if this problem is frequent in other plants. And of course, how other engineers has solved this problem. I already created a Control Language Program which track important instruments going to PID controllers in order to detect step changes and automatically set the controller in MANUAL mode. But this algorithm doesn't work for smooth increasing o decreasing signal fails.