UT_SIGNAL_SELECT — Redundant sensors (2 or 3 transmitters)

Combines two or three transmitters measuring the same thing into one trusted
value, and alarms when they disagree. Bad sensors are dropped automatically.

Pins

Record UT_SELECT_DATA

How it works

• An input is good when its GoodN is TRUE and its value is a number (NaN and
  infinity are dropped even with GoodN TRUE).
• When an input goes bad it is simply left out, so Out moves by no more than the
  spread there was between the inputs (use filterTime to smooth even that).
• Deviation and the spread Fault are UT_PROTECTs with the
  delays above; they clear as soon as the spread is back below the limit.
• With no good input, Fault is on at once and noGoodAction gives Out
  (MIN, MAX and PASS leave out NaN / infinity; with nothing usable Out holds).

Using it

Press(In1 := PT1.Value, In2 := PT2.Value, In3 := PT3.Value,
      Good1 := PT1.Good, Good2 := PT2.Good, Good3 := PT3.Good, Data := PressSelCfg);