Siemens SINUMERIK 840D Description Of Functions page 271

11.03
System variables Images of the PLC-side external SPL output signals (status signals from PLC-
$A_OUTSEPD[1,2] SPL) can be read double-word-serial (32bit) via these system variables.
Associated DB18 values:
System variables Images of the PLC-side SPL markers can be read via these system variables.
$A_MARKERSIP[1..64]
Associated DB18 values:
System variables Images of the PLC-side SPL markers can be read double-word-serial (32bit) via
$A_MARKERSIPD[1,2] these system variables.
Associated DB18 values:
Direct single-channel communications between NCK and PLC-SPL. Signals
System variable
$A_PLCSIIN can be written by the PLC and read by the NCK.
System variable Direct single-channel communications between NCK and PLC-SPL. Signals
$A_PLCSIOUT can be read by the PLC and written by the NCK.
General information The system variables are updated in the same clock cycle as the crosswise
about system data comparison between the NCK and the PLC.
variables $A_xxxP(D) These system variables can only be accessed reading.
These system variables may only be used in the commissioning phase.
As soon as commissioning has been signaled as completed, access to these
system variables is disabled. If these program commands are processed, this is
indicated as an error with Alarm 17210.
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Note
Write access operations to all named system variables
$A_OUT..../$A_MARKER... and $A_TIMERSI is only possible from the
program saved in program file /_N_CST_DIR/_N_SAFE_SPF reserved for the
SPL. Access operations from other programs are flagged as an error with
Alarm 17070.
4 Data Descriptions
4.4 System variable
DB18.DBD46, DBD50
DB18.DBX70.0 ... DBX77.7
DB18.DBD70, DBD74
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