Siemens SINUMERIK 840D Description Of Functions page 148

3 Safety-Related Functions
3.10 Safe programable logic (SPL) (840D SW 4.4.18)
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•
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.
Q1
Q2
TM1
CMP
>=
E1
AND
E2
E3
TI1
TI2
TI3
Fig. 3-35 Function chart of the "safety relay"
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.
OR
AND
Zeitmessung fallende
bis steigende Flanke
t4
E_AND
AND
t4i
© Siemens AG 2003 All Rights Reserved
11.03
A0
A1
Timer1
A2
Timer2
A3
Timer3