Using the maximum/minimum function, Using the maximum/minimum function -12 – Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX User Manual

Page 182

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10-12

Using the Function Block

Figure 10.14
Example of an Add/Subtract Function Block

An In 1 Value (parameter 96) receives input from a

±10V pot. An In 1

Offset (parameter 98) is set to 0 because no offset is needed. The
±10V input is converted to ±2048 internal drive units. An In 1 Scale
(parameter 97) is set to 2 to scale the value to

±4096, which is ±base

motor speed. This input is passed to Function In1 to use as the coarse
adjustment.

An In 2 Value (parameter 99) receives input from a 10V pot.An In 2
Offset
(parameter 100) is set to 0 because no offset is needed. The

10V input is converted to 2048 internal drive units. An In 2 Scale

(parameter 101) is set to 0.2 to scale the value to 409. This input is
passed to Function In2 to use as the fine speed adjustment.

In addition, you need to set bit 11, Bipolar Sref, in Logic Options
(parameter 17).

Using the Maximum/Minimum
Function

The maximum/minimum function lets you select either the larger of
two values or the smaller of two values. The maximum/minimum
function block is shown in Figure 10.15.

200

Func 1 Eval Sel

0

198

Function In1

199

Func 1 Mask/Val

Enter: 0 This value is not used.

Add/Subtract

Function Block

203

Func 2 Eval Sel

0

201

Function In2

202

Func 2 Mask/Val

Enter: 0 This value is not used.

212

Function Sel

9

In1 + In2

213

Function
Output 1

29

Speed

Ref 1

+10V Pot

+10V Pot

96

An In 1 Value

98

An In 1 Offset

97

An In 1 Scale

=0

=2.000

99

An In 2 Value

100

An In 2 Offset

101

An In 2 Scale

=0

=0.200

+10V

+2048

+4096

+409

Coarse

Adjustment

Fine

Adjustment

Enter 0 for parameters 204 through 211
as these parameters are not used for this
function block.

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