Spy

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You can use the spy in order to detect the position of movable elements. In reality you would therefore use rotational encoder, absolute encoder, potentiometer etc. In the last analysis all these elements have the task to deposit the position of another element somewhere in the PLC. The spy does exactly the same.

The spy detects the distance within the three space directions from his own position up to the position of the master. You must enter a DINT of the PLC for every space direction. If you need only one coordinate, you simply give the others a MD with a high number you do not use otherwise, e.g., MD 17000.

As in reality position detectors have different resolutions, you must decide inside the field ‘scaling’ how many units of the PLC-value have to be changed, if the master is relocated by about 1 mm.

In order to adjust the zero point of the spy, please proceed as follows: Bring the detected element to a position for which you know the value to be reported to the PLC. In case this element is hanging on a linear mover, you can shift it by the slide controller on its edit mask. Then you enter the value which is to be sent to the PLC into the fields ‘display’. That is all.

If you want to detect the position of the spy itself, e.g., if you have fixed it directly to the moving element for reasons of clearness, you need to specify the origin as master. In this case you should enter a negative value for the resolution to avoid the spy counting reversely.

For detecting the position of a linear mover, it is more suitable to use the linear mover with sensors.