Programming; Communication Via Part Programs/Synchronous Actions - Siemens SINUMERIK 840D sl Function Manual

Digital and Analog NCK I/Os (A4)
NCK I/O via PROFIBUS
1.3.3

Programming

Requirement
● Correct configuration of the corresponding I/O-ranges.
● PLC must actually be able to provide the required I/O-ranges (useful-data slots).
● The configured I/O-ranges are released for use only when the PROFIBUS-
1.3.3.1

Communication via part programs/synchronous actions

General
The NCK global system variables enable access to the PROFIBUS-I/O, whether read or
write, from the part programs/synchronous actions:
● $A_DPx_IN [n,m]
● $A_DPx_OUT [n,m]
Please note the following:
● When reading from or writing to these variables from the part programs, a preprocessing
● To ensure data consistency during programming from the part program and the
● If the same PROFIBUS-I/O data are to be write-accessed several times within an IPO
● The PROFIBUS-I/O data to be written is printed at the PROFIBUS-I/O only after the
Access I/O-range data
The following system variables are available for accessing the I/O-range data:
Table 1- 3 NCK → PROFIBUS-I/O
System variables
$A_DPB_OUT[n,m]
$A_DPW_OUT[n,m]
$A_DPSB_OUT[n,m]
$A_DPSW_OUT[n,m]
$A_DPSD_OUT[n,m]
$A_DPR_OUT[n,m]
n = index for the output data range; m = byte index for the data
60
communication interface is able to do a data exchange with the corresponding
PROFIBUS-I/O for the first time.
stop is triggered.
synchronous actions, the PROFIBUS-I/O data are accessed, which are kept consistent
for the respective IPO cycle.
cycle (e.g. synchronous actions, access from different channels, etc.), then the data of
the last write access respectively are valid.
corresponding IPO cycle.
Value
8 bit unsigned
16 bit unsigned
8 bit signed
16 bit signed
32 bit signed
32 bit REAL
Description
Writing a data byte (8 bit) to PROFIBUS-IO
Writing a data word (16 bit) to PROFIBUS-IO
Writing a data byte (8 bit) to PROFIBUS-IO
Writing a data word (16 bit) to PROFIBUS-IO
Writing a data double word (32 bit) to PROFIBUS-IO
Writing output data (32 bit REAL) to PROFIBUS-IO
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions