Operating instructions

Functions, monitoring, and protective functions
9.4 Extended functions
Drive converter cabinet units
362 Operating Instructions, 10/2008, A5E00288214A
Configuration of the load gear (p2720).
The following points can be set by configuring this parameter:
● p2720.0: Activation of position tracking
● p2720.1: Setting the axis type (linear axis or rotary axis)
Here, a rotary axis refers to a modulo axis (modulo offset can be activated through
higher-level control or EPOS). With a linear axis, position tracking is mainly used to
extend the position area (see section: Virtual multiturn encoder (p2721)).
● p2720.2: Reset position
The position values stored in a non-volatile fashion are reset for the following events:
– If encoder replacement is detected.
– If the configuration of the encoder data set (EDS) is modified.
– If the absolute encoder is re-calibrated.
Note
If position tracking of the load gear is activated after an adjustment (p2507=3) via parameter
p2720[0] = 1 (position gear load tracking) has been made, the adjustment will be reset.
Further adjustment of the encoder while the position tracking is activated will cause the load
gear position to be reset (overflow).
The permissible range of position tracking is mapped to the reproducible EPOS encoder
range.
It is possible to activate position tracking for several DDS.
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.
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.
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)
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.