Honeywell TDC 3000 System : Variable dead time Lag Lead Point


Thread Starter


Hello to all experts of this forum.

We have Honeywell's DCS - TPS/TDC3000.

In a drum level control loop there are two points created in the system whose implication I am unable to understand.

Tag 3FI3511 is created to read steam flow transmitter value. The compensated Steam flow tag, 3FY3511, is created by reading the steam temp, steam pressure and steam flow.

NOW, this value, 3FY3511, is 'fed' to a VARIABLE DEAD TIME LAG LEAD point, 3FY3511A. I donno what does this point do. The Equation in the help menu of this point tells that this point has one lead and two lags. What does this mean? The configuration page allows inputting values for constants like D1, C, Lead time value and two Lag time values. If compensated steam flow is say 50TPH then what should be the value of 3FY3511A? How will changing the values of Two Lag time constants and one Lead time constant affect the output of 3FY3511A?

thanks and regards