Functional Secondary Conditions - Siemens Sinumerik 840D sl Function Manual

Connecting Sensors/Actuators
7.2 Connecting I/O via PROFIsafe
Warning
!
Due to runtime differences in the NCK--SPL and PLC--SPL it cannot be
guaranteed that when several SPL output data are simultaneously changed that
these are then consistently transferred in the PROFIsafe telegram.
7.2.12

Functional secondary conditions

When connecting via SPL I/O using one safety--related bus (PROFIsafe), several
secondary conditions and constraints must be taken into consideration when con-
figuring and programming:
S Faults/errors in the PROFIsafe input devices (e.g. input signals that differ from
one another) cause the associated SPL input signals ($A_INSE(P)) to be dele-
ted (cleared). This initiates a STOP D/E.
S The transfer of the external SPL input signals in the DB18 interface for the
$A_INSEP variables is realized inside the system. Only one signal state for
both SPL channels is transferred to the master from the PROFIsafe input
peripherals.
S The external SPL output signals of the DB18 interface ($A_OUTSEP variables)
are transferred within the system to the relevant PROFIsafe output modules.
A signal state is transferred to the output modules via PROFIsafe.
S It may be necessary to use single--channel signals (signals that are present
only in the PLC or only in the NCK) to change over external SPL outputs (e.g.
brake control). These single--channel signals must also be made available to
the other program channel to align the logic and program synchronously. Direct
communications between the NCK and PLC--SPL via DB18 is a good way to
achieve this.
S In each PROFIsafe cycle, the PROFIsafe layer generates a PROFIsafe tele-
gram with the logically AND'ed SPL output data as F net (useful) data.
PROFIsafe components
As far as the PROFIsafe components that can be operated with a SINUMERIK
840D sl, the following limitations apply:
S PROFIsafe components with dynamic i parameters are not supported.
S The maximum possible F net data width for each PROFIsafe component is
96 bits.
S The value range for the F address of PROFIsafe component is as follows: 1 --
65535
D
7-232
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
or 1 -- FFFF
H
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