Siemens SINAMICS S120 Function Manual page 257

Absolute encoder adjustment
Absolute encoders must be adjusted while commissioning. After the machine has
been powered-down the position information of the encoder is kept.
When p2507 = 2 is entered, using the reference point coordinate in p2599, an off-
set value (p2525) is determined; this is used to calculate the position actual value
(r2521). Parameter p2507 signals the adjustment with a "3" – in addition bit
r2684.11 (reference point set) is set to "1".
The offset of the encoder adjustment (p2525) should be saved in a non-volatile
fashion (RAM to ROM) to permanently save it.
Caution
!
After the encoder has been adjusted, it must be ensured that the absolute encoder
does not overflow along the complete traversing range. If an overflow occurs, then
there is no clear reference any longer between the encoder actual value and the
mechanical system.
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
Extended Functions
Function module "basic positioner"
4-257