Siemens SINUMERIK 840D Description Of Functions page 159

11.03
3.10 Safe programable logic (SPL) (840D SW 4.4.18)
In order to be able to exchange SI-specific signals between the NCK and PLC
in a dedicated data area, a corresponding communication interface has been
introduced for these components. This allows SI applications running on the
NCK and PLC (SPL) to be able to communicate in separate data areas that
cannot be occupied by other system functions. On the PLC side, this interface
represents an extension of DB18; on the NCK side, new system variables have
been introduced for this interface and these are available to the user. The
meanings of the individual bits in this interface are defined by the user.
NCK
$A_PLCSIOUT[1...32]
$A_PLCSIIN[1...32]
For status queries on the PLC side, DB18 is supplemented by the SPL run-up
status already displayed on the NCK in the SI service display
NCK
-
Limitations System variables $A_PLCSIOUT[1...32] and $A_PLCSIIN[1...32] are protected
against access from other programs, except the NCK-SPL program
(SAFE.SPF). A corresponding programming command is rejected with the
Alarm 17070 "Channel %1 Block %2 Data write-protected".
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
3 Safety-Related Functions
PLC
DB18.DBD128 32 bits from NCK to PLC
DB18.DBD132 32 bits from PLC to NCK
PLC
DB18.DBW136 Bit 16 run-up status
3-159