A4: Digital and analog NCK I/Os for SINUMERIK 840D sl
1.3 Access via PROFIBUS
Extended Functions
54 Function Manual, 03/2013, 6FC5397-1BP40-3BA1
1.3 Access via PROFIBUS
1.3.1 Brief description
Function
The function "I/O access via PROFIBUS" implements a direct data exchange between the
NCK and the PROFIBUS I/O.
Availability
The function is available for isochronous and non-isochronous configured PROFIBUS I/O.
Hardware requirements
● The required PROFIBUS I/O must be available and ready to use.
● A correct S7 HW configuration (PLC-side) must be carried out with the required
PROFIBUS I/O, and loaded in the PLC.
● An I/O range must be present on the same PROFIBUS slave.
I/O range
If the individual user data slots of a PROFIBUS slave are configured in the S7 HW
configuration (PLC) in such a way that they form a contiguous PROFIBUS I/O section in
series, with logical start addresses in ascending order, then this section is referred to as I/O
range in the following.
An I/O range is characterized by:
● A logical start address (this corresponds to the logical start address of the first user data
slot of this I/O range).
● A configured length (this corresponds to the length in bytes of the connected PROFIBUS
I/O to be accessed).
The logical start addresses of the I/O range must be available in the NCK, so that it can
read/write the corresponding data of the PROFIBUS I/O via an NCK-internal PROFIBUS
communication interface. The configured I/O range is registered via machine data (see
"Configuration of the I/O ranges (Page 56)". The communication with the PROFIBUS I/O is
thus
possible only I/O range-oriented.