Specifications of the safety functions

System requirements

Required Firmware

  • v4.2.0 or higher

Supported Hardware

  • SOMANET Node 2000 Safety (E revision or newer) *

  • SOMANET Node 1000 Safety (E revision or newer)

  • SOMANET Node 400 Safety (E revision or newer)

* External fuse at main supply (48 VDC) is required for Node 2000 Safety dimensioned according to driven load.

Technical specifications

Safety parameters

Safety Integration level (SIL) according to IEC 61508:2010


Performance Level (PL) according to ISO 13849-1:2015

PL e cat. 3

Safe Failure Fraction (SFF)

99.99 %

Probability of dangerous failure per hour (PFH d)

1.07*10 -10 /hour

Probability of dangerous failure on demand (PFD avg)

9.41*10 -6

Common Cause Failure (CCF)


Hardware Fault Tolerance (HFT)


Reaction time

10 ms

De-activation time

10 ms

Mean Time to dangerous Failure (MTTF d)

3035 years (capped to 100 years)

Diagnostic coverage (DC avg)



Type A

Mission time T M

20 a

Supported safety modes

High, Low, Continuous

Geometrical properties


70 x 40 x 27.7 mm


96 g (incl. Heatsink)

Installation requirements

Max. installation altitude

2000 m

Pollution Degree

PD 2

Supported Motors

1 x 3-phase BLDC-Motor and 1 active brake


SOMANET Node Safety shall be used only in Pollution Degree environments class PD1 or PD2 according to IEC 61800-5-1: During normal operation only non-conductive pollution may occur, temporarily occurring conductivity caused by condensation may only be expected when the servo drive is out of operation.

Safe digital inputs (STO-SBC input)

Number of digital inputs

2 (dual-channel safety input for activating STO-SBC function)

Digital input type according to IEC61131-2:2007

Type 1

Voltage range

0-60 VDC

Max. transient input voltage

80 VDC

Input voltage, logic 1

15-60 V

Input voltage, logic 0

0-5 V

Input current

Max. 6 mA (@24 VDC)

Test pulse toleration (OSSD pulses)

Max. 1 ms

Reverse voltage protected


Allowed discrepancy between digital inputs

100 ms

Safe brake output (SBC)

Number of digital outputs

2 (dual-channel safety output for one brake system)

Max. output voltage

Servo drive main power supply (48 VDC)

Min. output voltage

0 V

Max. current.

1 A

Max. peak current.

4 A


This PWM controlled brake is configured by the same object as the regular brake.

Block diagram

Simplified block diagram of SOMANET Node Safety:


For details of the connectors please refer to: