PCC-IV Instruction Manual (Rev. 0.1)
Page 6-19
Section 6
– Blockware Functions
Technical Reference
F43
[L/L] Lead
– Lag with Gain (Dynamic Compensation)
Function
L/L
provides Lag, Lead, and Gain compensation in a single Block. Lag is a digital filter operation and is
the first operation performed on the Input. Lead is a Derivative (or Rate) operation, and is performed on the result
of the Lag filter. Gain is a simple multiplier that acts on the result of the Lead operation.
Lag and Gain operations can be used alone or in combination with any other operation. Lead requires Lag to be
non-zero, and the ratio: (Lead seconds / Lag seconds) must be less than 15.
The Lag seconds is the time it takes for a step Input to drive the Output to 63% of the Input change. A larger value
provides more damping.
The Lead Seconds is the derivative gain; that is: {Rate (%/Sec) * Lead (Sec) = %}. A larger value provides a larger
response to a signal change.
---------------------------------------------------------------------------------------------
NAME: L/L SINGLE USE FUNCTION: N OUTPUT TYPE: A
---------------------------------------------------------------------------------------------
Input Type Description Notes
_____________________________________________________________________________________________
1 A PV INPUT
Parameter Description Default Max Min Code Notes
_____________________________________________________________________________________________
1 LAG SECONDS 0 1800 0 2 1,2,3
2 LEAD SECONDS 0 1800 0 2 1,2,3
3 GAIN 1.00 20.00 0.01 2
Notes:
1. 0 = Off
2. Lag seconds must be greater than 0, if Lead is greater than 0
3. The ratio: (Lead Seconds / Lag Seconds) must be less than 15
F45
[SCALE] Signal Scaling
Function
SCALE
generates a Block Output based on two (X,
Y) scaling points. X is the Block Input, and Y is the Block
Output. The straight line defined by scaling points (X
1
, Y
1
) and
(X
2
, Y
2
) continues beyond the two defined points and
generates a Block Output within the +/- 327% limitations of the
Input and Output. See examples below:
Example 1
Example 2
Example 3
Input (X):
X
1
= 0
X
2
= 100
X
1
= 0
X
2
= 50
X
1
= 0
X
2
= 100
Output (Y):
Y
1
= 50
Y
2
= 0
Y
1
= 0
Y
2
= 100
Y
1
= 90
Y
2
= 110
---------------------------------------------------------------------------------------------
NAME: SCALE SINGLE USE FUNCTION: N OUTPUT TYPE: A
---------------------------------------------------------------------------------------------
Input Type Description Notes
_____________________________________________________________________________________________
1 A SIGNAL INPUT
Parameter Description Default Max Min Code Notes
_____________________________________________________________________________________________
1 X1 0.00 150.00 -150.00 2
2 Y1 0.00 150.00 -150.00 2
3 X2 100.00 150.00 -150.00 2
4 Y2 100.00 150.00 -150.00 2
-50
0
50
100
150
-50
0
50
100
150
O
utput(Y
)
Input (X)
Graph of Example 3
