Sto Feedback - Danfoss iC7 Series Operating Manual

Operating Guide | iC7 Series Functional Safety
Asynchronous input tolerance: The input signals at the safe input terminals are not always synchronous. If the discrepancy
l
between the 2 signals is longer than 500 ms, the drive indicates an IO failure as described in
activation of the safety function.
STO Ch. A/B
Ch.A
Ch.B
Discrepancy time
STO function
Active
Inactive
Figure 3: Discrepancy Time

STO Feedback

3.3.6
STO feedback is a single-channel feedback signal which can be used for status information. It can help to achieve better safety capability
on system level, for example, in retrofit cases, where diagnostic feedback to the safety system is required.
The feedback signal is not designed to be a part of the safety function, and it does not have a Safety Integrity Level.
Table 3: Instances of STO Feedback for Systems with Modular Control
State
Standard function
STO state is reached
Configuration needed
Software update
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CAUTION
(1)
Feedback state
De-energized
Energized
De-energized
De-energized
Table 14. This feature does not delay the
Additional information
The motor is running and no safety function is active.
STO feedback is de-energized.
STO is requested, and a safe state is reached.
STO state is reached and connection to all power units
is established. STO output is de-energized.
Safe inputs must have a validated configuration to
ensure that all power units have reached a safe input
state. The connected power units are a part of the con-
figuration, and without a validated configuration, the
safe input cannot assume to have a connection to all
power units established.
During software update, the state of the safe output is
not reliable. STO output is de-energized.
AQ477043679710en-000102 / 172K2965A |
iC7 Functional Safety
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