Siemens SINUMERIK 840D sl Function Manual page 1592

Detailed description
2.6 Referencing with absolute value encoders
MD31020 $MA_ENC_RESOL (Encoder lines per revolution)
MD10050 $MN_SYSCLOCK_CYCLE_TIME (System clock cycle)
MD10070 $MN_IPO_SYSCLOCK_TIME_RATIO (Factor for interpolator cycle)
Note
The position control switching speed relevant for spindles is set according to the encoder
limiting frequency of the absolute value encoder of the spindle:
MD35300 $MA_SPIND_POSCTRL_VELO (position control switching speed)
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
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The limiting frequency corresponding to the limiting speed is calculated to be:
Basic logic functions: Reference Point Approach (R1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0