Detailed Description 
  2.7 Referencing by means of actual value adjustment 
Reference Point Approach (R1) 
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0 
2-41 
The limit frequency corresponding to the limit speed: 
MD36300 $MA_ENC_FREQ_LIMIT 
is calculated as follows: 
(4 * MD31020 $MA_ENC_RESOL) / (MD10050 $MN_SYSCLOCK_CYCLE_TIME * 
MD10070 $MN_IPO_SYSCLOCK_TIME_RATIO) 
 
 
 
Note 
The closed-loop positioning speed: 
MD35300 $MA_SPIND_POSCTRL_VELO 
that is relevant for spindles must be set in accordance with the encoder limit frequency of 
the absolute encoder of the spindle: 
MD36300 $MA_ENC_FREQ_LIMIT (encoder limit frequency).  
 
2.6.9  Referencing variants that are not supported 
The following referencing variants are not supported when used with absolute encoders: 
•  Referencing/calibrating with encoder zero mark 
•  Distancecoded reference marks 
•  BERO with two-edge evaluation 
2.7  2.7 Referencing by means of actual value adjustment 
2.7.1  Actual value adjustment to the referencing measurement system 
Functionality 
When actual value adjustment to the referencing measuring system is performed, the 
resulting absolute actual position after successful referencing of the measuring system of a 
machine axis is transferred directly to all other measuring systems of the machine axis, and 
the machine axis is designated as referenced: 
DB31, ... DBB60.4/60.5 (referenced/synchronized 1/2) = 1 
Advantage 
When the machine axis switches from an explicitly referenced measuring system to the 
measuring system referenced by actual value adjustment, continuous servo control is 
assured (servo enable active) because the matched actual position prevents a sudden 
change in actual value.