Technical data

Drive functions

7.3 Function modules

Function Manual

Function Manual, 06/2012, 6SL3097-4AB10-0BP4

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Virtual multiturn encoder (p2721)

The virtual multiturn resolution is used to set the number of resolvable motor rotations for a

rotary absolute encoder with activated position tracking. It can be edited only for rotary axes.

With a rotary absolute encoder (p0404.1 = 1) with activated position tracking (p2720.0 = 1),

p2721 can be used to enter a virtual multiturn resolution.

Note

If the gear factor is not equal to 1, then p2721 always refers to the load side. The virtual

resolution, which is required for the load, is then set here.

For rotary axes, the virtual multiturn resolution (p2721) is preset to the value of the multiturn

resolution of the encoder (p0421) but may be changed.

Example: Singleturn encoder

Parameter p0421 is preset to p0421 = 1. However, parameter p2721 can be altered

subsequently, e.g. the user can program p2721 = 5. As a result, the encoder evaluation

initiates 5 load rotations before the same absolute value is achieved again.

For linear axes, the virtual multiturn resolution (p2721) is preset to the multiturn resolution of

the encoder (p0421) extended by 6 bits (max. overflows 32 positive/negative)

The value for p2721 cannot be edited again afterwards.

Example: Multiturn encoder

For a linear axis, the value for p2721 is set to 262144 for an encoder with p0421 = 4096.

That means, +/- 131072 encoder revolutions or load revolutions can be reproduced in this

way.

If, as a result of extension of the multiturn information, the displayable area of r2723 (32 bits)

is exceeded, the fine resolution (p0419) must be reduced accordingly.

Tolerance window (p2722)

After switching on, the difference between the stored position and the actual position is

ascertained and, depending on the result, the following is triggered:

Difference within the tolerance window → the position is reproduced based on the current

actual encoder value.

Difference outside the tolerance window → an appropriate message (F07449) is output.