Efficient Networks S120 manual Tolerance window p0413, Commissioning

Basic functions 6.14 Position tracking

Tolerance window (p0413)

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 (F7449) is output. The tolerance window is preset to quarter of the encoder range and can be changed.

NOTICE

The position can only be reproduced if, in the powered-down state, the encoder was moved through less than half of the range that it can represent. For the standard EQN1325 encoder, this is 2048 revolutions or half a revolution for singleturn encoders.

Note

The ratio stamped on the gearbox type plate is often just a rounded-off value (e.g.1:7.34). If, for a rotary axis, it is not permissible to have any long-term drift, then the actual ratio of the gearbox teeth must be requested from the gearbox manufacturer.

Note regarding using synchronous motors with a measuring gearbox

Field-oriented control of synchronous motors requires a clear reference between the pole position and encoder position. This reference must also be carefully maintained when using measuring gearboxes: This is the reason that the ratio between the pole pair number and the encoder revolutions must be an integer multiple ≥ 1 (e.g. pole pair number 17, measuring gearbox 4.25, ratio = 4).

Commissioning

The position tracking of the measuring gearbox can be activated in the drive wizard (STARTER) during the configuration of the drive. During the configuration there is an item for encoder parameterization. In the encoder dialog, click on the "Details" button and activate the checkbox for position tracking in the displayed dialog.

The parameters p412 (Measuring gearbox, rotary absolute encoder, revolutions, virtual) and p413 (Mesasuring gearbox, position tracking tolerance window) can only be set via the expert list.

6.14.2.3Prerequisites

●Absolute encoder

●Firmware release ≥ 2.4

●CU310 or CU320 with Order No. 6SL3040- ....- 0AA1 and Version C or higher

Drive Functions	211
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4