Specifications

General programming notes
8.4.1
General
8
-6
8.4 Interface structure
8.4.1 General
The interface between PLC and NC is implemented by the exchange of data blocks (DB)
and functions (FC) between them. The PLC sends external information to and receives sta-
tus information from the NC.
The following four groups of information are transferred through the interface:
• NC kernel (NCK) information
• Mode group information
• Channel information
• Feed/spindle information
8.4.2 Signals through the PLC/NC interface
The flow of signals through the interface is illustrated below.
PLC user
program
MMC
NC
NKC
MMC
Tool
management
Mode group
NC channel
Feed/
spindle drive
DB31
38
Feed/spindle drive
signals
DB71
73
Tool management
signals
DB21/22
M, G, and S code
DB19
MMC signals
DB11
MMC, machine-side
operation panel mode
signals
DB10
PLC/NC signals
DB9
Standard NCK signals
DB2
PLC messages