calculated with a different equation depending on whether the acceleration is able to reach the selected ramp rate (A1) or not. If the required change

is small the selected ramp rate is not reached and the ramp does not include the central linear ramp region. If the required change is larger the ramp

does include the central linear region as shown in the diagram above.

Speed

Δw*

= 1000 x J / A1

linear

where:

A = selected ramp rate

J = Pr 2.07

If the required change is less than Δw*

used.

= 2 √ (Δw* x Pr 2.07 / 1000)

Ramp1

= (Δw* x A / 1000) + (Pr 2.07 / A)

Ramp2

The default values for the ramp rate and S ramp acceleration limit have been chosen such that for the default maximum speed, the curved parts of the

S ramp are 25% of the original ramp if S ramp is enabled. Therefore the ramp time is increased by a factor of 1.5.

2.10

Acceleration rate selector

Bit

Coding

Range

0 to 9

Default

Update rate

4ms read

The acceleration rate is selected as follows.

Ramp rate selection by terminal input

1 - 8

Ramp rate defined by parameter number, i.e. 1 = Pr 2.11, 2 = Pr 2.12, etc.

Ramp rate selection by Pr 1.50

When Pr 2.10 is set to 0 the acceleration ramp rate selected depends on the state of bit Pr 2.32 to Pr 2.34. These bits are for control by digital inputs

such that ramp rates can be selected by external control. The ramp rate selected depends on the binary code generated by these bits as follows:

Pr 2.34

Pr 2.33

When Pr 2.10 is set to 9 the appropriate acceleration rate is automatically selected depending on the value of Pr 1.50, and so an acceleration rate can

be programmed to operate with each reference. Since the new ramp rate is selected with the new reference, the acceleration applies towards the

selected preset if the motor needs to accelerate to reach the preset.

Mentor MP Advanced User Guide

Issue Number: 1

Parameter description

Parameter x.00

format

should be used, but if the speed change is greater or equal to Δw*

then T

linear

Ramp1

Txt VM DP ND RA NC NV