Siemens SINUMERIK 840D sl Function Manual page 612

M5: Measuring
8.2 Hardware requirements
PROFIBUS-DP drives
It is possible to operate a distributed probe directly on the PROFIBUS-DP drive for the
SINUMERK 840D with an NCU 573.2/3/4. This method is more accurate than NC
interpolation of cyclic position values from a centralized probe.
The type of measuring function for PROFIBUS-DP drives, e.g., with SIMODRIVE 611
universal, is specified by the following machine data:
MD13210 $MN_MEAS_TYPE
Value = 0: A probe connected centrally to the NC or
Value = 1: A distributed probe wired for all drives.
SIMODRIVE 611 universal drives support the measurement functionality of distributed
probes by storing the actual encoder value in the hardware concurrent to the measurement
signal edge. The more accurate measurement method for a distributed probe is preferred for
PROFIBUS-DP drives.
SIMODRIVE 611 digital drives continue to be operated with a centralized probe at connector
X121 on the SINUMERIK 840D/840Di.
References:
/BHA/ User Manual, Absolute Value Sensor with PROFIBUS-DP
/FBU/ Function Manual of SIMODRIVE 611 universal
612
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions