Parameterization - Siemens Simatic Manual

Fail-safe function blocks for storage and retrieval machines
4 Parameterizing error retraction velocity
5 Actual position invalid
6 Actual velocity invalid
7 Reserved
8 Reserved
9 Actual velocity too high regarding ac-
tual position and direction
10 Reserved
11 Reserved
12 Reserved
13 Reserved
14 Reserved
15 Reserved
3.6.3 Principle of operation
3.6.3.1

Parameterization

1. The user must interconnect the safety-related position actual value of the system to be moni-
tored at SAFE_POS, and at input POS_VALID its validity AND'ed with the valid reference
(REFERENCED). Block "F_SAFE_POS" (Chapter 3.2) provides three signals as output.
2. It also behaves the same with inputs SAFE_V and V_VALID, which refer to the safety-related
actual velocity.
3. The lower end stop is parameterized using input X_NEGATIVE and the positive end stop us-
ing X_POSITIVE.
4. The velocity envelope curve of the end zone to the monitored is parameterized in a perma-
nently assigned fail-safe data block for the residual distance to an end stop with a maximum
distance of 9999 SLU. Correspondingly, the velocity envelope curve is symmetrical in the
positive and negative end zones. As a consequence, the fail-safe data block comprises 10000
velocity values, whose index corresponds to the residual distance in SLU, the initial value
saved at the index, the maximum permissible velocity at this position in SLU/min.
5. The fail-safe data block must be structured as follows, and the name maintained:
6. The velocity envelope curve must start at index 0 (≙ 0 SLU) with 0 SLU/min, velocity values
parameterized higher than the value parameterized at V_MAX, are limited to V_MAX.
7. VMAX_RELEASE must lie in the range 1 – V_MAX. The block identifies if values less than 1
or values higher than 32767 are parameterized, and DIAG bit 4 is set. ERROR changes to 1.
S7-Distributed Safety/SIMATIC Safety - fail-safe function blocks for storage and retrieval machines
0 < VMAX_RELEASE parameterized <= V_MAX
Actual position valid again
Actual velocity valid again
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SAFE_V <= SLS_THRESHOLD and positive edge
at ACK
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