If Variable Selector 1 Mode (K32) = 10 then the variable selector can be used to provide a sectional control function. (Variable selector 2 operates in

the same way.) The sectional control function is intended to apply scaling and a speed offset to a 16 bit position value to generate a new 16 bit

position value. The output can be used as an input to the Standard motion controller (Menu 13) and to generate an encoder simulation output (Menu

3).

Position input

Speed input

The position input is selected with Variable Selector 1 Source 1 (K30) 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. Drive Encoder Position (J53)). The input is scaled so that as Variable Selector 1 Source 1

Scaling (K34) 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 (K34) = 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.

The range of Variable Selector 1 Output (K29) 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 0.1 rpm. Full scale of the source parameter corresponds to 1000.0 rpm. Scaling may be

applied using Variable Selector 1 Source 2 Scaling (K35) to give a full scale value up to 4000.0 rpm. 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 4 ms 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 7500 rpm.

E300 Design Guide

Issue Number: 1

Electrical

Getting