840Di-specific data and functions
18.2 Expanded message frame configuration/evaluation of internal drive variables
Manual
600
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
18.2.6
Constraints
Slot assignment
The NC always occupies an entire slot. The data of the slot not used by the NC, e.g. data
from the extended message frame configuration therefore, cannot be written by the PLC
user program.
Constraints
The following restrictions are applicable with regard to the "expanded message frame
configuration" function:
●
Additional data can only be transferred from the drive to the SINUMERIK 840Di sl NC
(actual value channel). You cannot transfer data in the other direction, i.e. from the NC to
the DP slave drive (setpoint channel).
●
You can only have read access to the drive data stored in the system variables.
Consistency check
When the SINUMERIK 840Di sl boots, the NC checks the consistency of the parameters
relevant to the process data configuration of the cyclic PROFIBUS communication:
●
NC
–
MD13060 $MN_DRIVE_TELEGRAM_TYPE[n] (drive message frame type)
●
DP master (configuration)
–
DP slave properties: Setpoint: Length
–
DP slave properties: Actual value: Length
●
Drive
–
Message frame selection
–
PDA setpoint assignment
–
PDA actual value assignment
If the number of process data expected by the NC, parameterized via the message frame
type in NC machine data MD13060 $MN_DRIVE_TELEGRAM_TYPE[n] (drive message
frame type) is bigger than the number configured with STEP 7 HW Config for the DP slave
drive (DP slave properties: Setpoint: Length/DP slave properties: Actual value: Length) or if
the process data configuration for the drive parameters does not match the message frame
type for the NC machine data, then the following alarm is displayed:
●
Alarm 26015 "Axis
axis identifier machine data $MN_DRIVE_TELEGRAM_TYPE[index]
value not permissible".
