Activation By Safe Digital Inputs

When activated by using safe digital inputs, a safety device with test pulses is required (OSSD, (see "OSSD")).

Safe inputs must be driven from a source containing test pulses, this can be a safe digital output or a safety device with suitable outputs. If the SMM is configured to detect distinct test pulses, then no fault exclusion is required against wiring shorts and cross-talk.

Electromechanical devices such as relays and emergency stop switches can be wired in series with a source of test pulses; the B10d value of the mechanical contacts may limit the achievable safety level.

Safety Level

Single Safe Input

Dual Safe Inputs

SIL2, PLd Cat. 3

ü

ü

SIL3, PLe Cat. 4

—

ü

Safety functions that monitor motion require a safe encoder. The safety properties of the safe encoder may limit the achievable safety level.

Dual Channel Activation

Safety Function

ISO 13849-1

IEC 62061

Maximum
Response Time

Comment

STO

PLe, Cat.4

SIL 3

< 10 ms

 

SS1-t

PLe, Cat.4

SIL 3

< 10 ms

followed by STO*

SS1-r

PLe, Cat.4, SIL 3 or
PLd, Cat.3, SIL 2
(limited by the safe encoder)

< 10 ms

followed by STO*

SS2

followed by SOS

SOS, SSM, SSR, SCA, SDI,
SLA, SLI, SLP, SLS, SAR

 

* = configured delay (time to STO) see AXIS#.SAFEPARAM.SS1_#.TIMETOSTO

Dual channel for axis1 and axis2, Safety Control with electronic outputs, automatic restart:

Dual channel for axis1 and axis2, Safety Control with relay contacts, automatic restart:

Dual channel for axis1 and axis2, Emergency Stop, automatic restart (example for default configuration):

Dual channel for axis1 and axis2, Emergency Stop, manual restart:

Single Channel Activation

Safety Function

ISO 13849-1

IEC 62061

Maximum
Response Time

Comment

STO

PLd, Cat.3

SIL 2

< 10 ms

 

SS1-t

PLd, Cat.3

SIL 2

< 10 ms

followed by STO*

SS1-r

PLd, Cat.3

SIL 2

< 10 ms

followed by STO*

SS2

PLd, Cat.3

SIL 2

< 10 ms

followed by SOS

SOS, SSM, SSR, SCA, SDI,
SLA, SLI, SLP, SLS, SAR

PLd, Cat.3

SIL 2

< 10 ms

 

* = configured delay (time to STO) see AXIS#.SAFEPARAM.SS1_#.TIMETOSTO

Single channel for axis1 and axis2, Safety Control with electronic outputs, automatic restart:

Single channel, 2 axes, Safety Control with relay contacts, automatic restart (distinct pulse monitoring must be disabled):

Single channel for axis1 and axis2, Emergency Stop, automatic restart:

Single channel for axis 1, Emergency Stop, manual restart: