Safety relays

Your Benefits

  • Reduce commissioning work thanks to quick installation and wiring with a single front connector
  • Quick module exchange thanks to the simple one-click mounting rail release
  • Significant space savings in the control cabinet with a 20% thinner housing compared to the predecessor version
  • Design machines more compactly and benefit from faster processes thanks to short response times and reduced safety distances
  • Increase machine availability with comprehensive diagnostic options
  • Long service life even in highly dynamic processes with many switching cycles


High ease of use, more space in the control cabinet, quicker production starts, more compact machines with shorter safety distances and reduced downtime: With the clever ReLy safety relay, you get even more out of your application, and that with high safety at performance level e. So don’t rely on just any safety relay – use the ReLy from SICK. Thanks to clearly defined areas of application, selecting the right variant is simple as can be.

At a glance
  • Clever, user-friendly housing functions
  • Thin design with construction widths from 18 mm
  • Fast response times of under 10 ms (depending on the type)
  • Status LEDs and diagnostic interfaces
  • Variants for universal application and for safe series connection with Flexi Loop available


SICK All in One Campaign Image
SICK All in One Campaign Image


Whether photoelectric sensors, inductive sensors, magnetic sensors, ultrasonic sensors, safety switches, RFID, encoders, or bar code scanners - order now at particularly favorable special prices in the My SICK web shop!

More information 


Easy handling, efficient operation

You can always relay on the ReLy. Thanks to its clever functions, it provides more efficiency in a simple way. You benefit from fast production startup, reduced downtime and more compact machine designs.
The thin, user-friendly housing ensures space- and cost-efficient installation and commissioning
Quick troubleshooting and restart of your application thanks to diagnostic LEDs as well as controllable lamps and reset pushbuttons
More compact machine designs and faster processes as a result of shorter response times and reduced safety distances

With the ReLy, you get more out of your applications thanks to the high level of usability.

Versatile application, simple selection

From the simple evaluation of a safety light curtain to time-delayed switching: The ReLy has the right variant for any requirement and can thereby be used in nearly any of your applications. This means you can remain flexible in your operations and rely on productivity-enhancing safety concepts from SICK.
Safety sensors of any kind can be monitored with a high level of safety in a wide variety of applications
The RLY3-LOOP1 in combination with the Flexi Loop ensures safe and cost-efficient series connection of safety sensors
The RLY3-MULT1 multifunctional relay can be configured using DIP switches and is also suitable for complementary safety sensors

The ReLy offers you the right safety relay for any application.


Technical overview

  • Technical data overview

    Technical data overview

    ApplicationsEvaluation unit / output expansion module for OSSDs / evaluation unit for stop category 1 applications
    Safety integrity level

    SIL3 (IEC 61508)

    SILCL3 (IEC 62061)

    CategoryCategory 4 (ISO 13849-1)
    Performance levelPL e (ISO 13849-1)
    Sensor monitoring

    Discrepancy monitoring

    Cross-circuit detection

    Sequence monitoring

    Typical response time

    10 ms

    12 ms

    79 ms

    Configuration methodHard wired / hard wired / DIP switch
    Housing width18 mm / 28 mm
All technical data can be found accompanying the individual product