Safe Direction (Sdi) - Siemens SINAMICS S120 Function Manual

3.2.9

Safe Direction (SDI)

Definition according to EN 61800-5-2:
"The SDI function prevents the motor shaft mov-
ing in the wrong direction."
Examples of how the function can be used
Example
A protective door must only be opened if a drive
moves in the safe direction (away from the opera-
tor).
When replacing the pressure cylinders of the
plates, the drive must only move in the safe direc-
tion of rotation.
Once the protection against jamming has been
triggered, a roller shutter gate must only be able to
start moving in one direction.
At an operational limit switch, the trolley of a crane
must only be able to start in the opposite direction.
How does SDI function in detail?
SDI monitors the actual direction of rota-
tion.
The SDI setpoint limit can be transmitted
to the higher-level motion controller (e.g.
SIMOTION) to enable limitation of the
velocity setpoint there.
In addition, you can configure the set-
point limit provided by SDI as maximum
speed in the ramp-function generator. In
this case, SDI limits the speed setpoint to
the permissible direction.
You can select to block either the positive or the negative direction of rotation via 2 fail-safe
signals (F-DIs or PROFIsafe).
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
Overview of Safety Integrated functions
3.2 Safety Integrated Extended Functions
Possible solution
Select SDI in the converter using a fail-safe
•
input or PROFIsafe .
Enable the locking mechanism of the pro-
•
tective doors via the PROFIsafe status bit of
the converter.
Select SDI in the converter using a fail-safe
•
input or PROFIsafe .
In the converter, inhibit the direction of rota-
•
tion that is not permitted.
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