Siemens SINUMERIK Series Function Manual

A4: Digital and analog NCK I/Os for SINUMERIK 840D sl
1.2 Access via PLC
Extended Functions
Function Manual, 03/2013, 6FC5397-1BP40-3BA1
51
1.2.6.2 Supplementary conditions
Configuration
● If the PLC I/Os are to be written/read via the fast data channel, they must always be
configured as a cohesive block (i.e. no address gaps within this block).
● It must be possible for the number of bytes that have to be transferred to be mapped
without gaps on the PLC I/Os.
Time response
The time when the data is read in from the PLC I/Os is not synchronized with the time when
the data is 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
variable was assigned within the data buffer.
● If values are assigned to several system variables simultaneously (e.g. for initializing the
PLC I/Os), there is no guarantee that they will be transferred in the same interpolation
cycle.

Siemens SINUMERIK Series Specifications

General

Axes Control	Up to 31 axes
Category	Control Unit
Manufacturer	Siemens
Series	SINUMERIK
Control Type	CNC
Communication Interfaces	Ethernet, USB
Operating Temperature	0°C to 45°C
Protection Class	IP20
Power Supply	24V DC
Display	Color TFT LCD