3 Safety-Related Functions
11.03
3.10 Safe programable logic (SPL) (840D SW 4.4.18)
© Siemens AG 2003 All Rights Reserved
3-148
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
•
$A_LEVELSID: indicates for how many signals different levels can
currently be detected on the NCK and PLC side.
•
In addition, other NC variables or free R parameters can be written to
monitor internal states of the SPL.
The following applies to all system variables of the NCK-SPL outputs:
They can be written from and read back to the SPL program.
3.10.6
Safe software relay (from SW 6.3.30)
The standard SPL module "safe software relay" is designed to meet the
requirements of an emergency stop function with safe programmable logic.
However, it can also be used to implement other similar safety functions, e.g.
control of a protective door. Parameter FirstRun must be switched to the value
TRUE via a retentive data (memory bit, bit in data block) at the first run-through
after the control has run-up. The data can be preset, e.g. in OB 100. The
parameter is reset to FALSE when FB 10 is executed for the first time.
Separate data must be used for parameter FirstRun for each call with separate
instance.
OR
AND
AND
Timer1
Timer2
Timer3
A0
A1
A2
A3
E1
E2
E3
t4
Zeitmessung fallende
bis steigende Flanke
AND
CMP
>=
t4i
TM1
Q1
Q2
TI1
TI2
TI3
E_AND
Fig. 3-35
Function chart of the "safety relay"