The position input is selected with Variable Selector 1 Source 1 (12.008) and can be derived from any parameter. However, it is intended to be used with

a position value that has a range from 0 to 65535 (e.g. P1 Position (03.029)). The input is scaled so that as Variable Selector 1 Source 1 Scaling (12.013)

is changed between -4.000 and 4.000 so the proportion of the input position change added to the accumulator varies from 0.000 to 2.000 (i.e. the change

of position input value is added without scaling if Variable Selector 1 Source 1 Scaling (12.013) = 0.000). The remainder from the scaling division is stored

and then added at the next sample to maintain an exact ratio between the position input and the position output, provided the speed from source 2 is zero.

The controller only takes the change of position from the input source parameter, and not the absolute value, so that when the controller is first made

active the output does not jump to the source position, but only moves with any changes of source position after that point in time.

Although the sectional controller is intended to use a source parameter with a range from 0 to 65535, it is possible to use parameters with a different

range provided the maximum is a power of two minus 1, i.e. 2

- 1. It should be noted that the change of position is scaled based on the maximum of the

parameter, and so a signed position value such as P1 Normalised Position (03.058) which has a maximum that corresponds to half its range will give

twice the change of position when compared to P1 Position (03.029). To counteract this effect the scaling applied to the change of position in the sectional

controller should be set to 0.5.

The range of Variable Selector 1 Output (12.012) is 0.00% and 100.00%. Unlike other functions the value is not simply limited, but rolls under or over

respectively. Although the output destination can be any parameter it is intended to be used with a position value that has a range from 0 to 65535.

The speed input defines a speed offset with a resolution of 0.1rpm. Full scale of the source parameter corresponds to 1000.0rpm. Scaling may be applied

using Variable Selector 1 Source 2 Scaling (12.014) to give a full scale value up to 4000.0rpm. The speed input is added to the accumulator to move the

output position forwards or backwards with respect to the position input.

The sample time for the variable selector is 4ms and the input or output position must not change by more than half a revolution over this time. Therefore

the input or output speed must not exceed 7500rpm.

The diagram below shows an example of how the sectional controller function could be configured. The section input position is provided from the

previous section via the P1 position feedback interface. The destination of the variable selector is the Standard Motion Local Reference Position

(13.021) in the standard motion controller which is used to provide the speed reference and to control the local motor attached to the drive. The encoder

simulation system is used to generate the section output to be fed into the next drive. The source for the encoder simulation is

Standard Motion Local Reference Position (13.021).

Powerdrive F300 Parameter Reference Guide

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Issue: 01.15.00