Siemens SINUMERIK 828D Function Manual page 865

NCK/PLC signals
The group of signals from the NCK to PLC includes:
• Actual values of the digital and analog I/O signals of the NCK
• Ready and status signals of the NCK
Also output in this group are the HMI handwheel selection signals and the status signals.
The signals for handwheel selection are decoded by the basic program and entered in the machine-/axis­specific
interface.
Digital/analog inputs/outputs of the NCK
The following must be noted with respect to the digital and analog inputs and outputs of the NCK:
Inputs:
• All input signals or input values of the NCK are also transferred to the PLC.
• The transfer of signals to the NC parts program can be suppressed by the PLC. Instead, a signal or value can
be specified by the PLC.
• The PLC can also transfer a signal or value to the NCK even if there is no hardware for this channel on the
NCK side.
Outputs:
• All signals or values to be output are also transferred to the PLC.
• The NCK can also transfer signals or values to the PLC even if there is no hardware for this channel on the
NCK side.
• The values transferred by the NCK can be overwritten by the PLC.
• Signals and values from the PLC can also be output directly via the NCK I/O devices.
Note
While realizing the digital and analog NCK I/Os the information contained in the following
documentation must be taken into account:
References:
Functions Manual Extended Functions; Digital and analog NCK I/Os (A4)
Signals PLC/Mode group
The operating mode signals set by the machine control panel or the HMI are transferred to the operating mode
group (BAG) of the NCK. On the 840D, these are valid for all NCK channels. On 840D systems, several mode
groups can optionally be defined in the NCK.
The mode group reports its current status to the PLC.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
P3: Basic PLC Program for SINUMERIK 840D sl
13.7 Interface structure
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