Baldor VS1GV21-1B Installation & Operating Manual page 145

11.1 Overview
This reference is mathematically computed from any two valid drive parameters. Once configured, it can provide a signal to
drive the speed loop, torque loop or process PID. In addition, this reference can drive all existing operating modes including
the PLC Mode. Composite Ref can be referenced to any valid input:
P1402 - Command Source
P2603 - Process PID Feedback Source
Mathematical operations are performed at each stage in its development providing the ability to add, subtract, multiply or
divide any two parameters to form a complex internal reference source. This reference source can influence the operation of
all existing operating modes including PLC Mode. The Composite Reference Parameter Block is programmed in the Level 3,
Composite REF parameters.
Stage 1 (P#3501 & 3507)
Scale Factor
Variable A P
x
P
y
Output is = ± 100%
Stage 1 (P#3503 & 3508)
Scale Factor
Variable B P
a
P
Output is = ± 100%
ID Function
0
1
2 | X |
3 1/X
4 X
5 √(|X|)
6 Sin(x)
7 Cos(x)
8 Ramp(x)
9 Freq(x)
ID Function
0
1
2
3
4 Max
5 Min
MN765
P2310 - Auxiliary Filter Source
P1418 -Torque Feedforward Source
Figure 11-1 Composite Reference Generator Block Diagram
Stage 2 (P#3502)
Math Function
P P
P
y y
* K
=
x
1 P
z
Max P
x
Stage 2 (P#3504)
Math Function
P P
b b
P * K
=
a 2
P
c
b
Max P
a
Table 11-1 Math Functions (P3506)
Description
0 Zero
X Identity
Absolute Value
Inversion
Square
2
Square Root
Sine
Cosine
Ramp Generator
Frequency Generator
Table 11-2 Binary Operator Selection Parameter (P3505)
Description
+ Sum
- Difference
• Multiply
/ Divide
Maximum
Minimum
Composite Reference Description
P
z
=
F(P )
y
Stage 3 (P#3505)
P
z
Binary Operator
P
c
=
R
P
x
c
=
F(P )
b
1. Zero Function, F(x) = 0
1
2. Identity Function, F(x) = x
2
3. Where, |x| is the absolute value function:
3
|x|= x for x ≥ 0
|x|=-x for x < 0
4. The ramp generator is computed as follows:
0.0
Constant output for x = 0
3
0.0
With time period equal to 1.0/(|x|•100) Sec
5. The frequency generator is computed
as follows: y = Ramp(x) Freq(x) = Sin(2πy) With
output frequency equal to |x|•100 Hz
4
5
1. Y = Max(x, y) provides the maximum
2. Y = Min(x, y) provides the minimum
1
2
Chapter 11
P1415 - Current Limit Source
P2604 - Process PID Setpoint Source
Stage 4 (P#3506)
Math Function
with Limit Setting
R R
x x
=
R F(R
y
(P )O(P )
c z
Notes
1.0 for x > 0
-1.0 for x < 0
Notes
Composite Reference Description 11-1
R
y
R
y
)
x