Wiring the safety inputs

Attention

For SIL 3, PL e, cat.3 it is required to send test pulses from the PLC to the output or to ensure fault exclusion for wiring “Short circuit between any two conductors” according to ISO 13849-2:2012 between signals STO-SBC 1 and STO SBC 2

  • permanently connected (fixed) and protected against external damage, e.g. by cable ducting, armouring, OR
  • separate multicore cables, OR
  • within an electrical enclosure, OR
  • individually shielded with earth connection.

Connection diagrams for the STO inputs

Manual switch + drive

Allows safety functions up to SIL 3, PL e, cat.3.

../../../../_images/STO-SBC_switch_21.png

Manual switch + drive (single-channel)

Allows safety functions up to SIL 1, PL c, cat. 1.

../../../../_images/STO-SBC_single_switch1.png

Manual switch + multiple drives

Allows safety functions up to SIL 3, PL e, cat.3.

../../../../_images/STO-SBC_switch_nth1.png

Safety PLC PM (Plus-Minus output) + drive

Allows safety functions up to SIL 3, PL e, cat.3.

For example: Safety PLC digital output

../../../../_images/STO-SBC_PLC_PM1.png

Safety PLC PM (Plus-Minus output) + multiple drives

Allows safety functions up to SIL 3, PL e, cat.3.

../../../../_images/STO-SBC_PLC_PM_nth1.png

Attention

In case of multiple drive connection, ensure that the output driver has sufficient current driving capability.

Safety PLC PP (Plus-Plus output) + drive

Allows safety functions up to SIL 3, PL e, cat.3.

For example: Safety PLC output or safety sensors (e.g. Safety light curtain, safety scanner etc.)

../../../../_images/STO-SBC_PLC_PP1.png

Safety PLC PP (Plus-Plus output) + multiple drives

Allows safety functions up to SIL 3, PL e, cat.3.
../../../../_images/STO-SBC_PLC_PP_nth1.png

Attention

In case of multiple drive connection, ensure that the output driver has sufficient current driving capability.

Connection diagrams for the STO/SBC feedback output

The STO-SBC feedback can be used for safety diagnostic purposes

The STO/SBC feedback can be used as an indication of safe state of the drive/system (e.g. LED).

Attention

STO/SBC feedback shall not be used as a safety function!

Note

STO/SBC feedback is not mandatory for reaching SIL 3 or PL e safety levels

High side driver

../../../../_images/STO-SBC-FB_high1.png

Low side driver

../../../../_images/STO-SBC-FB_low1.png

Connection diagram for the brake

Attention

When using a safe brake ensure to connect the safe brake GND to Brake- instead of a general GND

../../../../_images/STO-SBC_wiring_brake1.png

Now you are ready to use the feature:

Safety functions