Safe Programmable Logic (Spl); Basic Principles - Siemens SINUMERIK 840D sl Function Manual

05.08
7.3

Safe programmable logic (SPL)

7.3.1

Basic principles

Function
These signals must be logically combined (interlocked) in a safety–related, freely
programmable form in order to be able to flexibly process safety–related external
process signals and safety–related internal input and output signals. The "Safe
Programmable Logic" (SPL) handles this task as an integral system component.
Features:
S Logic operations implemented by the user are cyclically processed.
S Instructions are effective in all operating modes.
S The PLC program immediately starts to execute the instructions after the con-
trol has booted.
S The SGE/SGA must be supplied by the machine manufacturer – both in the
drive monitoring channel as well as in the NCK monitoring channel.
S The NCK–SPL is written as ASUB using the CNC function synchronous ac-
tions. The PLC–SPL is written as PLC user program.
In order to check that the two SPLs (PLC and NCK) are functioning, the system
program arranges cyclic data comparison between the PLC and NCK.
Max. 64 safety–related sensors
can be directly connected
(e.g.: mode switch, light
barriers, Emergency Stop,...)
Fig. 7-21
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
SGE
Crosswise result and
data comparison
SGE
Safe programmable logic
Connecting Sensors/Actuators
7.3 Safe programmable logic (SPL)
SGA
NCK–SPL
Max.
actuators can be connected
(e.g.:
interlocking, motor brakes, ...)
PLC–SPL
SGA
64 safety–related
protective door
7-223