Constraints; Nck I/O Via Plc - Siemens SINUMERIK 840D sl Function Manual

1.4

Constraints

1.4.1

NCK I/O via PLC

Availability of the function "digital and analog NC inputs/outputs"
Digital and analog CNC inputs/outputs (DI, DO, AI, AO) are available as follows:
● SINUMERIK 840D with NCU 571
● SINUMERIK 840D with NCU 572/573, SW 2 and higher
Analog I/Os for 840Di
The analog I/Os are connected to the SINUMERIK 840Di via PROFIBUS-DP.
Configuration
● If the PLC I/Os are to be written/read via the fast data channel, they must always be
● It must be possible for the number of bytes that have to be transferred to be mapped
Dynamic response
The time when the data are read in from the PLC I/Os is not synchronized with the time
when the data are made available to the part program via system variables!
Data transfer (NCK <--> PLC)
● The data buffer is always output complete to the PLC I/Os, even if only one system
● If values are assigned to several system variables simultaneously (e.g., for initializing the
Extended Functions
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
4 DI/4 DO (on board)
32 DI/32 DO with expansion via NCU terminal block
4 DI/4 DO (on board)
32 DI/32 DO and 8AI/8AO with expansion via NCU terminal block
configured as a cohesive block (i.e., no address gaps within this block).
without gaps on the PLC I/Os.
variable was assigned within the data buffer.
PLC I/Os), there is no guarantee that they will be transferred in the same interpolation
cycle.
Digital and analog NCK I/Os (A4)
1.4 Constraints
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