Honeywell HC900 - I;O Network

Design and Implementation of HC900 Control System - Allowable Function Blocks for Process and Safety Functions
32 HC900 Process & Safety Controller Safety Manual Revision 1.9
01/14
Auxiliary Blocks
Function
Generator
Generate output characteristic curve based on up to
11 configurable "Breakpoints" for both input (X) and
Output (OUT) values. OUT = interpolation of OUT
(Yb) values for segment in which X falls. If X <= X(1),
then OUT = OUT(1). If X >= X(11), then OUT = OUT
(11). ATTENTION: The X(n) value must be < X(n+1)
value. Thus, if fewer than 11 breakpoints are needed,
be sure to configure any unneeded breakpoints with
the same X and OUT values used for the previous
breakpoint.
X
X
Lead Lag
Modifies an analog input value (X) to include LEAD
(T2) and LAG (Tl ) time constants of from 0 to 99
minutes, when a digital input (EN) is ON.
X
X
High-Low Limiter
Provide high-low limit for an analog (X) value. Turns
ON HI or LO digital output if input exceeds or falls
below set limits. If X < or = Low Limit value, then:
OUT = LoLlM; L = ON; H = OFF. If X > or = High Limit
value, then: OUT = HiLlM; L = OFF; H= ON. If X >
Low Limit value and < high Limit value, then: OUT =
X; L = OFF; H = OFF.
X
X
Velocity Limiter
Limits the rate at which an analog input value (X) can
change, when a digital input signal (EN) is ON.
Individual rate of change limits is configured for an
increasing and a decreasing X, respectively.
Separate digital status outputs indicate when High(H)
or Low(L) rate limits are active. If EN = OFF or
system state = NEWSTART, then: OUT = X, L =
OFF, H = OFF. If EN = ON and OUT < X, then: OUT
moves toward X at Increasing RATE limit, L = OFF, H
= ON until OUT = X. If EN = ON and OUT > X, then:
OUT moves toward X at Decreasing RATE, L = ON
until OUT = X, H = OFF.
X
X
Rate of Change
Provides an analog output representing units per
minute change of the analog input. Compare
setpoints for high and low rate of change. Compare
selections for increasing, decreasing or both
directions of change. A logic 1(ON) output when input
rate exceeds high rate setpoint. A logic 1(ON) output
when input rate is less than the low rate setpoint.
X
X