Using the add/subtract function, Using the add/subtract function -10 – Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX User Manual

Page 180

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10-10

Using the Function Block

Figure 10.11
Speed Profiler Using the State Machine Function Block

In addition, you need to set three other parameters for this example to
work. Speed Ref 1 (parameter 29) needs to be set to the base motor
speed (4096 internal units). Accel Time 1 (parameter 42) and Decel
Time 1
(parameter 44) both need to be set to 2 seconds.

Using the Add/Subtract
Function

The add/subtract function adds the value of function input 1 to the
value of function input 2 and places the result in Function Output1
(parameter 213). Figure 10.12 shows the add/subtract function block.

Figure 10.12
Add/Subtract Function Block

D

Speed

(internal

units)

Time (seconds)

4000

1024

0

A

B

C

E

F

G

0

1

2

3

4

At point A, a start command has been received and the motor speed can
begin to follow the specified acceleration ramp.

At point B, the motor speed has reached 1024 internal units. Because
In2 (Motor Speed (parameter 81) > 1024) becomes true while In1
(Motor Speed > 4096) is still false, the state machine uses In7 (Ramp
Disable) as the output sent to Function Output1 (parameter 213) which is
linked to Logic Cmd Input (parameter 197). The motor speed increases
using the current limit.

At point C, In1 (Motor Speed > 4096) becomes true and the timer on
function runs for 10 seconds (D) as specified by In5. After 10 seconds,
the stop command becomes true, and the motor speed decreases using
the current limit.

At point E, Motor Speed is less than 4096 so the drive is again using In7
(Ramp Disable). The stop is removed.

At point F, Motor Speed is less than 1024 and with both In1 and In2
being false, In3, which is 0, is used for Function Output1. The motor
continues decelerating using the specified deceleration ramp.

200

Func 1 Eval Sel

0 – 17

198

Function In1

199

Func 1 Mask/Val

I

V

Add/Subtract

Function Block

203

Func 2 Eval Sel

0 – 17

201

Function In2

202

Func 2 Mask/Val

I

V

212

Function Sel

9

In1 + In2

In1

In2

213

Function Output 1

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