Siemens SINUMERIK 840Di sl Commissioning Manual page 601

No acyclic communication possible
If a drive does not support acyclic communication, of if the acyclic communication via the
following axis-specific NC machine data was switched off explicitly for a drive, a consistency
check of the above-mentioned data is the sole responsibility of the person who performs the
startup:
● MD13070 $MN_DRIVE_FUNCTION_MASK[n] (Used DP functions)
Manual
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
18.2 Expanded message frame configuration/evaluation of internal drive variables
WARNING
For system purposes, the consistency check, which is performed when the SINUMERIK
840Disl boots and which is based on acyclic communication with the drive, is performed
in conjunction with the cyclical communication - which is already active - between NC
and drive.
As setpoint and actual values are already being exchanged between the NC position
control and drive as part of the cyclic communication, uncontrolled system states can
occur on the part of the drive due to faulty process data configurations which cannot be
detected yet at this point in time.
The same applies if acyclic communication is not supported by a drive, or if acyclic
communication was deactivated for a drive via the axis-specific NC machine data and
hence, no consistency check by NC is possible:
• MD13070 $MN_DRIVE_FUNCTION_MASK[n] (Used DP functions)
Therefore, the responsibility lies with the commissioning engineer to implement suitable
measures to avoid uncontrolled traversing of the drives during startup, caused by
inconsistencies in the above mentioned data.
An error can present a risk of danger to person or machine.
840Di-specific data and functions
601