P4: PLC for SINUMERIK 828D
14.5 Data interface
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
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14.5
Data interface
Data is cyclically exchanged on one hand between the PLC and NC and and on the other hand between the PLC
and HMI. This especially means that the data received from HMI and destined for the NC must be marshaled by
the user program in order that these become effective.
Data to the PLC are provided by the firmware at the start of the user program cycle. This ensures, for example,
that the signals from the NCK remain constant throughout a cycle.
Data from the PLC are transferred by the firmware to the NKC or HMI at the end of the user program cycle.
All data of this interface are listed in the manual for SINUMERIK 828D, PPU.
14.5.1
PLC-NCK interface
These cyclic data include, e.g. status signals ("Program running", "Program interrupted"), control signals (Start,
Stop) and auxiliary and G functions.
Data are structured in signals for:
• Mode signals
• NC channel signals
• Axis and spindle signals
• General NCK signals
• Fast data exchange PLC-NCK
14.5.1.1
Mode signals
DB3000, 3100
The mode signals specified by the machine control panel or the HMI are transferred to the NCK.
There actual states are signaled to the PLC from the NCK.