MR381 Emergency Actuator

May 5, 2016
MR660 Multi-Axis Fiber Optic Accelerometer
February 7, 2017

MR381 Emergency Actuator

MR387 E-Stop
MR387 E-Stop


Emergency Actuator Sensor

The MR381 Series Emergency Actuator (E-ACTUATOR) Switch is a new, innovative emergency signalling system that can be deployed where EMI immunity is required, in hazardous environments or over long distances – beyond the capabilities of conventional electromechanical solutions. The MR381 E-ACTUATOR system employs a photo interrupt scheme operating over either a duplex multimode or duplex single mode optical link.

The MR381 E-ACTUATOR is designed for safety applications where a system is not to be activated or powered, such as a fire suppression system, until the E-ACTUATOR is deliberately pushed and engaged. A malfunction of the system shall not activate the emergency event.




ISO 13850 ISO 13850 defines the characteristics and requirements for a traditional electromechanical E-STOP switch. The MR387 Sensor/Controller integrates the definition of purpose and functionality only.
ISO 13849 Category 2 for MR380/MR381 E-ACTUATOR Sensor/Controller System
Functional Safety MR381 Sensor/Controller System = Category 2 per ISO 13849-1
MTTFd 6.20E+05 hours (70.8 years)
Performance Level PL=c
Safety Integrity Level SIL=1
Safe Failure Fraction SFF=97.85%
Diagnostic Coverage DC=75.76%
Functional States MR380 Controller Output States
Normal RESET (Up Position)

Red LED is ON

Digital 5V and 24V Outputs=LOW

Relay NC contacts=Open, Relay NO contacts=Closed

ACTIVATED (Down Position)

Broken Fiber, Loss of Optical Signal, or Controller Failure

Red LED is OFF

Digital 5V and 24V Outputs=HI

Relay NC contacts=Closed, Relay NO contacts=Open

Optical Interface
Interface Duplex LC for pigtailed sensors, MR381-X-YY where YY is pigtail length in meters
ODVA IP-LC connector receptacle, MR381-X-D00 sensors in housing
Insertion Loss

MR381-2-XX, IL=2.5dB max (2dB typical), 62.5/125 OM1 MM Fiber

MR381-3-XX, IL=3.5dB max (3dB typical), 9/125 OS1 SM Fiber

MR381-5-XX, IL=3.5dB max (3dB typical), 50/125 OM2/OM3 MM Fiber

Explosive Atmospheres Inherently Safe, Simple Mechanical Device
EX Classification Inherently safe, simple mechanical device when used with MR380 Multimode Controller
IECEx Test Report GB/CML/ExTR 16.0105.00/00
IEC Ex EPL Mb/Gb/Gc/Db/Dc
NEC Exempt
Temperature/Humidity -40°C to +65°C (-40°F to +150°F), 0-95% RH, Non-Condensing
Ingress Protection IP61
Housing Aluminum body, anodized finish
Durability 100,000 operations min.
Housing Dimension Consult Mechanical Reference Drawing
Mounting Consult Mechanical Reference Drawing
Unit Weight Sensor with 5 meter pigtail, 240 g (8.5 oz)


Specifications subject to change without notice


  • Sensor is EX  classified “inherently safe, simple mechanical device”
  • Sensor can be operated in any hazardous or explosive environment – gas, dust or mines
  • Immune to EMI, RFI, lightning, and ground loops
  • Immune to high voltage lines
  • Panel mountable sensor
  • DIN rail mountable controller
  • Controller provides DPDT relay and digital signal outputs
  • Operates over long distances – up to 2500 meters
  • Multiple E-STOP switches can be connected in series


Call 805.389.6600