Using the scale function, Using the scale function -20 – Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX User Manual

Page 190

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10-20

Using the Function Block

The previous example assumes that both D1 & D2 have motor speeds
of equal rating. Applications where motor speeds differ provide an
even greater example of the flexibility of this function block.

To set up this application, you need to enter the values shown in
Figure 10.24.

Figure 10.24
Multiply/Divide Function Block

In this example, per unit math is used because the value coming in
through An In 1 Value (parameter 96) is in internal units. The output
value is also in internal units.

Using the Scale Function

You can use the function block to set up a scale function. With this
function block, you enter the input range and the output range, and
the scale function block scales the input so that it stays within those
ranges. The scale function block is shown in Figure 10.25.

1024 (IN1) x 16777 (IN2) x 65536

4096 (IN3)

=

WHL

1062

=

(32 bit out)

274,874,368 (dec)

4000 Hex

P213

Fract
P214

200

Func 1 Eval Sel

0

198

Function In1

199

Func 1 Mask/Val

Enter: 0 This value is not used.

Multiply/Divide

Function Block

203

Func 2 Eval Sel

0

201

Function In2

202

Func 2 Mask/Val

Enter: D1/D2; where D1 is the diameter of the lead drive's spindle

and D2 is the diameter of the smaller spindle.

Enter: 0 This value is not used.

212

Function Sel

12

(An In 1 Value x (D1/D2))/4096
(In1 x In2)/In3

In4: Use per unit math.

213

Function
Output 1

206

Func 3 Eval Sel

0

204

Function In3

205

Func 3 Mask/Val

Enter: 4096

Enter: 0 This value is not used.

207

Function In4

Enter: 0

214

Function
Output 2

29

28

Speed Ref 1

Speed Ref

1 Frac

96

105

29

An In 1 Value

An Out 1 Value

Speed Ref 1

Lead Drive

Enter 0 for parameters 208 through 211
as these parameters are not used.

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