Fig. 15 Safe Outputs From A Third-Party Manufacturer Connected To Sto Inputs; Fig. 16 Safe Outputs From A Third-Party Manufacturer Connected To Sto Inputs Without The Use Of Test Pulses - Beckhoff AX8-1 Series Documentation

Use of the STO function
Using the STO inputs with a third-party safety controller
It must also be ensured that test pulses are generated when using a third-party safety controller or safe
output. The user must ensure that the test pulse length and frequency do not lead to a switch-off of the STO
channels or the AX8911. A filter with a filter time of 3.5 ms is implemented within the logic of the AX8911.
Safety assessment
When using a third-party safety controller, the safety assessment must be carried out by
the user or the machine manufacturer.
Attention
Fig. 15: Safe outputs from a third-party manufacturer connected to STO inputs
If the safety controller is unable to implement test pulses at the outputs, but instead supplies only static
24 V signals, the user must implement the wiring in such a way that a fault exclusion is permitted for the
DC
wiring. Further information about fault exclusions can be found in EN ISO 13849-2.
protected wiring
If no test pulses are used on the signals between the outputs of the safety controller and
the STO inputs of the AX8xxx-x1xx, the wiring must be implemented in the form of pro-
WARNING
tected cable laying (see also EN ISO 13849-2).
Fig. 16: Safe outputs from a third-party manufacturer connected to STO inputs without the use of test pulses
32 Version: 1.0.0 AX8911 - TwinSAFE Drive Option