Siemens Simatic Manual page 60

Fail-safe function blocks for storage and retrieval machines
SAFE_V
SAFE_POS
POS_TOLERANCE
VMAX_RELEASE
V_VALID
POS_VALID
FDBACK_DRIVE
FDBACK_BR_1
FDBACK_BR_2
SBT_SELECTED
SBT_ACTIVE
SBT_ACTIVE_BR
SBT_FDBACK_DIR
S7-Distributed Safety/SIMATIC Safety - fail-safe function blocks for storage and retrieval machines
Safe actual velocity [SLU/mm]
is supplied from the F_SAFE_POS block.
If the brake test was not successfully completed and if the actual
Int velocity is greater than the upper limit parameterized at
VMAX_RELEASE, then output SLS_OK is reset and the machine
is stopped.
DIAG bit 2 is additionally set for this particular case.
Safety actual position [SLU]
is supplied from the F_SAFE_POS block.
This is required to monitor standstill during the brake test. If the
Int axis moves by more than the value parameterized at
POS_TOLERANCE, then the test is considered not to have been
successfully completed and is exited.
DIAG bit 3 is additionally set for this particular case.
Threshold for standstill detection [SLU]
If, during a brake test, the axis moves by more than this absolute
value, then the test is exited and is considered not to have been
Int
successfully completed.
DIAG bit 3 is additionally set for this particular case.
POS_TOLERANCE >= 0
Retraction velocity [SLU/min]
If the test was not successfully completed, then this value is out-
put at SLS_THRESHOLD until a brake test has been successful-
Int
ly completed.
VMAX_RELEASE must be parameterized in the range 1-32767.
Otherwise, DIAG bit No. 4 is set
Actual velocity valid
is supplied from the F_SAFE_POS block.
1: velocity is plausible
Bool
0: velocity is not plausible, e.g. the increase of the deviation be-
tween the two encoders over time is outside the tolerance band
DIAG bit No. 6 is set if a 0 signal is present here.
Actual position valid
is supplied from the F_SAFE_POS block.
1: position is possible
Bool
0: position is not plausible, e.g. the discrepancy between the two
encoders is outside the tolerance band.
DIAG bit No. 5 is set if a 0 signal is present here.
Brake control, normal operation
Bool 0: close brake
1: open brake
Feedback signal, brake 1
Bool 0: open
1: closed
Feedback signal, brake 2
Bool 0: open
1: closed
Drive feedback signal – SBT selected
Bool 1: SBT selected
0: function not selected
Drive feedback signal – SBT status
1: test running; drive establishes a torque against the closed
Bool
brake
0: test not active; drive is passive
Drive feedback signal – active brake
The drive signals back the number of the actually tested brake:
Bool
0: brake 1
1: brake 2
Drive feedback signal – direction of the torque being estab-
lished
Bool
Here, the drive signals back the direction of the torque currently
being established:
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