Siemens SINUMERIK 840D sl Function Manual page 1602

Supplementary conditions
3.1 Large traverse range
Supplementary conditions
• Linear axes with a traversing range > 4096 encoder revolutions, rotatory absolute value
• Endlessly turning rotary axes with absolute encoders:
• Machine axes with absolute encoders:
56
encoder EQN 1325 and a parameterized absolute value encoder range of
MD34220 $MA_ENC_ABS_TURNS_MODULO = 4096:
– The maximum possible travel range corresponds to that of incremental encoders.
– Any number of integer transmission ratios are permitted.
– We recommend that you parameterize endlessly turning rotary axes with absolute
encoders as modulo rotary axes (traversing range 0 to 360 degrees).
MD34220 $MA_ENC_ABS_TURNS_MODULO
Otherwise, the machine axis may require a very long traverse path to reach absolute
zero when the measuring system is activated.
– To ensure that the NC correctly determines the current actual position when the
measuring system is reactivated, the machine manufacturer / user must ensure that
the machine axis is moved less than half the assigned traversing range when the
measuring system is deactivated (POWER OFF, "parking" selected).
MD34220 $MA_ENC_ABS_TURNS_MODULO
Basic logic functions: Reference Point Approach (R1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0