Functionality Of The Spl Input/Output Data - Siemens Sinumerik 840D sl Function Manual

Connecting Sensors/Actuators
7.4 Safety- -related CPU- -CPU communication (F_DP communication)
Warning
!
Depending on the application, the user must invert the status signals of an
F_SENDDP--/F_RECVDP connection (e.g. $A_FSDP_ERROR[1...n],
$A_FSDP_SUBS_ON[1...n], $A_FRDP_ERROR[1...n],
$A_FRDP_SUBS_ON[1...n], $A_FRDP_SENDMODE) when further processing in
the SPL. This is done in order to ensure a safe state in the case of incorrect
behavior/response of the PLC or NCK.
Example:
If $A_FRDP_SENDMODE is to be output as safety--related signal from the SPL to
PROFIsafe, then this signal must first be inverted. This is done in order that the
fail--safe value "0" also corresponds to the safe state, i.e. it has the significance
"deactivated safety mode".
7.4.15

Functionality of the SPL input/output data

Only the user (machinery construction OEM) defines the functionality of the SPL
input/output data within the scope of the F_DP communication.
The SPL programs of NCK--SPL and PLC--SPL are not executed synchronously
(from a time perspective). Brief differences in the output data of the two SPL
programs (NCK: $A_OUTSE, PLC: $A_OUTSEP) can occur due to the runtime
differences in the SPL programs.
In order that PLC and NCK--F_SENDDP use identical F net data when generating
an F telegram through two channels, the SPL output data are exchanged alternat-
ing between the two channels (PLC: $A_OUTSEP and NCK: $A_OUTSE) in each
F_DP clock cycle and are then AND'ed before the sending. For safety reasons, the
user (machinery construction OEM) must select the functionality of an SPL input/
output data so that the value "0" corresponds to the safe state of the functionality
represented by this data. Only then can it be absolutely ensured that the appro-
priate function is only activated on CPU2 (F_RECVDP) if the function is activated
in both SPL programs (PLC--SPL and NCK--SPL) of CPU1 (F_SENDDP).
Warning
!
For safety reasons, this is the reason that the functionality of an SPL input or
output data is selected so that the value "0" corresponds to the safe state of the
functionality represented by this data.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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