Technical specifications

The SOMANET Circulo series is a combination of servo drive, position feedback sensor (encoder), mechanical integration solution, providing an integrated brake option and is also available with safe motion functionality, specifically designed for collaborative robot (cobot) joints and smart actuators.

Power Specification


Circulo 7

Circulo 9

Maximum peak output power

750 W

1850 W

Maximum continuous output power

250 W

630 W

Nominal supply voltage *

24-48 V DC

Maximum supply voltage *

58 V DC cont.; 60 V DC peak

Minimum supply voltage *

14 V DC

Maximum input current DC

18 A

45 A

Maximum continuous phase current **

8 Arms

20 Arms

Maximum peak phase current ***

24 Arms

60 Arms

Maximum peak phase current (sine amplitude) **** 33.6 A 84 A

Maximum efficiency

> 98 %

* Please consider these definitions for supply voltage

** Maximum continuous values can be reached when the thermal mounting guidelines have been considered.

*** Please refer to the load cycle

**** An explanation for the different values used can be found in our System Integration Guide.

General Specification

  Circulo 7 Circulo 9
Supported Communication Standard EtherCAT with Safety over EtherCAT
(EtherCAT is a registered trademark and patented technology licensed by Beckhoff Automation GmbH, Germany)
Number of Phases 3
Supported motors BLDC, PMSM
Integrated safety functions STO/SBC according to SIL 3, Pl e
Integrated Encoder 1 (multi-turn with battery) (optional) 19 bit, absolute (optional) 20 bit, absolute
Integrated Encoder 2 (optional) 19 bit, absolute (optional) 20 bit, absolute
Incremental Encoder max frequency (external encoder) 1.4 MHz (supports up to 14,000 rpm with a 4,096 resolution incremental encoder)
Hardware protections Overcurrent, Overvoltage, Undervoltage, Overtemperature[1], PWM deadtime, PWM shoot through
Dimensions (see also dimension drawings)

Inner diameter: 20 mm

Outer diameter: 72.2 mm

Height: 21.3 mm

Inner diameter: 40 mm

Outer diameter: 92.2 mm

Height: 22.3 mm

Weight (without encoder rings) 92 g 133 g
Operating temperature

0 - 60°C ambient air (inside the enclosure)

0 - 70°C on the mounting surface (typically B-side / bearing flange of the motor)

Max. installation altitude 2000 m
Storage temperature -35 to 85° C
Humidity Max 90 % rH
Sensors on-board 3 x Iphase (two phases measured, one computed), UDC, tmosfet, tcore
Encoder port 1 1 x BiSS-C / SSI
Encoder port 2 1 x ABI / Fast ABI [2] / BiSS-C / SSI / A-Format / HALL
Brake power output 1 A @ 48 V
Brake peak current 4 A
Digital I/O

5x Digital IO (3.3/5 V)

1x Digital Output (3.3/5 V)

1x Digital Input (24 V)

(Safe) Digital I/O

1x Safe Digital Output (24 V)

2x Safe Digital Input (24 V)

3x Digital IO (3.3/5 V)

1x Digital Output (3.3/5 V)

1x Digital Input (24 V)

Analog In

1x Analog In Single Ended (0-5 V)

1x Analog In Differential (±5 V)

Motor temperature sensor input (user configurable) 1 x KTY (for example KTY84-130) / PT1000 / PT100 [3]
Heatsink Aluminum
Integrated brake Yes (optional)
Compliance with standards

CISPR 11 Class B (EN 55011:2016)

IEC 61000-4-6:2013

IEC 61000-4-3:2020

IEC 61000-4-2:2008

IEC 61000-4-8:2009

IEC 61800-5-1:2022

IEC 60204-1:2016

IEC 61158-6-12: 2019

IEC 61800-7:2015


Compliance with European directives CE (EMC Directive 2014/30/EU, Machinery Directive 2006/42/EC)

[1] The Hardware is protected against overtemperature above 114 °C. Since the software has its own temperature protection object which is set to 100 °C by default, this hardware protection will not be triggered.

[2] Fast ABI is supported from firmware 5.0 on

[3] Using a PT100 is not recommended. Click here for details about temperature sensors

Optional Integrated Brake

Brake specifications


Solenoid actuator

Detailed specifications