Function Blocks
Function Block Reference Guide
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AMB Function Block,
continued
Example
Figure 2-6 shows an function block diagram using an AMB function block
PT
MAIN STEAM
HEADER PRESSURE
PLANT MASTER
PRESSURE
CONTROLLER (PID)
OUT
-5 TO 105
TO AIR/FUEL
CONTROL (SP)
TO AIR/FUEL
CONTROL (SP)
OUT
-5 TO 105
OUT
-5 TO 105
IN
BOILER 1
SUBMASTER
BOILER 2
SUBMASTER
IN
BOILER
AMB Block (Boiler Submaster):
Operators place AMB Block to “MAN” mode to adjust fuel setpoints
up or down independent of each boiler.
AMB: OUT = IN + BIAS
MAN MODE
Bias is automatically calculated as operator increment or
decrement out value. Bias = OUT – IN
AUTO MODE
Bias is a fixed value from the man mode calc. Above
OUT = IN + Bias
Figure 2-6
AMB Function Block Example