Composite Reference Examples - Baldor VS1GV21-1B Installation & Operating Manual

Stage P#
1 3501 & Scale Factor - Monitor a parameter number (Variable A or B) and scales the value into percentage of
3503 maximum value for use by the next stage. As an example, P3501=5 Motor Voltage (assume its maximum
is 230V) is monitored and internally 20% is computed for P5= 46 V or 10% for P5=23 V. Likewise, with
P3503=11 then Speed Demand (assume its maximum is 60 Hz) is monitored and 50% is output when
P11=30 Hz or –50% when P11= -30 Hz.
P3501 or P3503 can be can be set to any valid drive parameter number. If either is set to an invalid
parameter number Py=0% or Pb=0%.
P3501 or P3503 only point to a valid parameter number in the active parameter table, never a parameter
outside the active table. Switching parameter tables with the drive enabled causes the Composite
Reference to be redefined by the parameter values in the new active parameter table.
2 & 4 3502,
Math Function - These parameters select the mathematical functions to be applied at the second and
3504 &
fourth stage of the Composite Reference's derivation. Refer to Table 11-1.
3506
3 3505 Operator - This parameter provides the mathematical operation to be performed at the third stage of the
Composite Reference derivation. Refer to Table 11-2.
1 3507 & These parameters provide a way to scale up or down the percentage calculation of the first stage. They
3508 range from -1000.00 to 1000.00 with default 1.00. Normally, the defaults work so these parameters need
not be changed.
A simple example of their use is: A 5A motor is connected to a 15A (peak) drive. When the motor is at
rated amps only 5/15 or 33.3% is passed on to stage 2, but by setting P3507=3.00, 100% is passed on
allowing full use of the motor's current.

11.2 Composite Reference Examples

The following table gives examples of the kinds of Composite References that may be developed.
P3501 P3502
P103 Identity
P103 Identity
P103 Identity
P102 Square
11-2 Composite Reference Description
Table 11-3 Composite Reference Parameters
Table 11-4 Examples
Composite Reference Parameters
P3503 P3504 P3505
P104 Identity Sum
P104 Freq Multiply
P104 Identity Divide
P104 Square Difference
Description
P3506 P3507 P3508
Identity 0.5 0.5
Identity 1.0 1.0
Identity 1.0 1.0
Square
1.0 1.0
Root
Description
Average of Analog Inputs 1&2:
R = (A +A )/2
y 1 2
Signal Generator with Magnitude
set by A1 and Frequency by A
R = A x Freq(A )
y 1 2
Ratio of Analog Inputs 1&2: R
Square Root of Difference of Squares
of Process Error and Analog2:
R = √(|P 2 – A 2 |)
y e 2
:
2
= A /A
y 1 2
MN765