DQE Series Safety Light Curtain Sensor and Safety Relay Connection Guide

The main link between safety light curtains and safety relays in the modern industrial automation system, and the reliable safety, is vital to the safe function of human and equipment. As such these safety light curtains are used extensively in stamping, machining, automated assembly line, etc in various situations.

Safety-output type, diagnostic pulse compatibility and protective capability must be confirmed for the exact order code; they cannot be assumed across the full catalog. This guide discusses DAIDISIKE DQE Series Safety Light Curtains are broadly used such as in stamping, machining, automated assembly lines, and other applications. We have detailed in this article the connection principle and we will take a brief step in each step, examples, and key consideration of both the DQE series safety light curtains and safety relays. It explains the engineering checks, not a pre-approved machine circuit.

Content updated: September 6, 2026. This model-level guide belongs to the light curtain installation and wiring index; the broader diagram library covers other interfaces. Keep actual terminal assignments separate from these functional explanations.

How to Connect a Light Curtain Safety Relay

The functional signal path is: Light Curtain OSSD1/OSSD2 → Safety Relay → Contactors/STO → Machine Stop. The selected relay must accept the exact light curtain's documented OSSD signals, and the complete stop circuit must be designed and validated for the machine. Compare the documented models before wiring: both DA31 and DQSRN are safety relay modules, but their reset and feedback functions are different.

For product selection before drawing the circuit, you can compare safety relay modules for light curtains. A standard delay relay cannot replace a safety relay in the protective stop function.

I. Principles and Prerequisites of Connectivity core.

This DQE example uses two OSSD (Output Signal Switching Device) outputs. Confirm the exact model's output type and published safety classification from its current manual; this page does not assign DQE a Type 2 or Type 4 classification. Safety relays such as DA31 and DQSRN accept only the curtain signals documented as compatible in the exact manuals. The selected relay switches the validated machine-stop circuit. Reset and EDM functions are model-specific. DA31 documents manual/automatic reset selection but not EDM feedback; DQSRN provides neither function.

II. General Wiring Process (dual OSSD, with DA31 reset selection)

1. Preparation before wiring

Isolate hazardous energy and verify the safe condition before wiring. The owner-confirmed DQE reference identifies white as OSSD1 and black as OSSD2; verify the delivered cable revision, supply, earthing and all terminal labels against its actual manual. Use the relay mounting and clearance specified for the supplied module, not a universal 5 cm rule.

Step-by-step wiring

(1) Power connection Verify supply voltage, permitted ripple, polarity, current demand and protective devices against both manuals. Use the specified supply and grounding arrangement. Brown and blue identification in this DQE reference is not a universal fuse rating or permission to share any power circuit.

(2) The OSSD signal connection (dual redundancy) Route the DQE white line (OSSD1) and black line (OSSD2) to the two safety inputs identified in the selected relay's exact manual. S1/S2 and CP are shown in the DQSRN example; do not transfer those terminal labels to DA31 unless its delivered manual confirms them. Match NPN/PNP polarity exactly as documented for both devices.

(3) Verify reset and EDM requirements before wiring DA31 factory material documents an SRC/SR selector for manual or automatic reset, but it does not state an EDM feedback function or a T1/T2 EDM path. DQSRN provides neither reset nor EDM. If the machine safety design requires contactor feedback, obtain an exact current manual that explicitly confirms EDM or select a controller that documents the function. Do not create a T1/T2 loop from an unrelated diagram.

(4) DA31-only reset function connection Configure the SRC/SR selector for manual or automatic reset exactly as shown in the delivered DA31 manual and as required by the machine risk assessment. Do not infer the selector state from this overview. DQSRN provides neither manual nor automatic reset, so this step does not apply to it.

(5) Shield and ground Distinguish protective earth from cable shield termination. Follow the specified conductor identification, bonding, cable routing and shield terminations in the sensor, relay and drive manuals. Neither single-ended grounding, a 4 ohm resistance nor a 200 mm cable spacing is a universal instruction for this combination.

Sample Connection (DAIDISIKE Safety Relay Adapted)

Example 1: DQE series (PNP type) + DA31 series safety relay

Example 2: DQE series (NPN type) + DQSRN series safety relay (2 outputs)

DQSRN accepts the documented OSSD input pair, but it does not provide manual reset, automatic reset or EDM feedback. Do not copy the DA31 SRC/SR reset wiring into this example, and do not add a T1/T2 EDM loop to either relay from an unrelated diagram. If the safety function requires monitored reset or contactor feedback, select a controller that explicitly provides those functions.

Verify the supplied DQSRN manual before assigning its supply, CP, safety inputs or output contact pairs. Do not transpose DA31 terminal names or copy the legacy 23/14 and 33/43 pairs: the final switching arrangement must use the actual module contact diagram. Confirm output count, NO/NC purpose, switching load and protective function rather than assuming an NC status contact is a safety output.

Need More Than Four Outputs? Custom Programmable Safety Control Projects

Some machines need more controlled output circuits than a standard safety relay provides. For qualified volume projects, DAIDISIKE can evaluate an engineering-to-order, PLC-programmable multi-output safety control architecture with five, six, seven, eight or more project-defined output circuits.

Custom development capability — not a catalog product. There is no fixed model, terminal map or off-the-shelf specification for this solution. Feasibility, safety architecture, testing, certification scope, development cost and minimum order quantity must be agreed before development begins.

What Can Be Evaluated for a Volume Project?

• Five, six, seven, eight or more project-defined output circuits.
• PLC-programmable logic based on an approved machine I/O matrix.
• Project-specific hardware, enclosure and output architecture.
• Integration requirements for documented safety inputs and final switching devices.
• Prototype, functional testing and required compliance evidence defined in the project plan.

Information Required for a Custom Evaluation

Project information	What the engineering team needs
Safety inputs	Exact light curtain, E-stop, guard-switch or other device models and output types.
Required outputs	Number of circuits, whether they act together or independently, and the required safe state.
Loads and interfaces	Contactor coils, STO interfaces, machine-control inputs, voltage and current requirements.
Control logic	Sequence, reset, feedback, diagnostics and fault-response requirements.
Risk and compliance	Machine risk assessment, target standards and evidence required by the destination market.
Commercial scope	Estimated project quantity, development schedule and validation responsibilities.

Have a volume project that needs more than four outputs? Send the machine I/O list, required logic, destination market and estimated quantity for an engineering feasibility review.

Request a Custom Project Evaluation

Check Before Power-on

Compare every conductor and terminal with the released project drawing and exact equipment instructions. Check isolation, shorts, polarity, permitted supply range, protective earth and shielding before energising. A multimeter continuity test does not validate OSSD pulse compatibility or the safety function.

Functional debugging

With hazardous motion prevented, verify the documented clear-field and interrupted-field output states. Do not assume a high output for every polarity or describe a normal protective trip as channels becoming out of step. Test both protective input channels and the resulting final-element response using the manufacturer-approved procedure; actual machine motion takes the measured system stopping time to cease. For a DA31 installation, test the selected reset mode exactly as its manual specifies; do not perform an EDM test unless an exact current manual explicitly documents that function. For DQSRN, stop after validating its documented OSSD trip and output behaviour: DQSRN has no reset or EDM function to test.

When adding PLC diagnostics after the protective circuit is defined, compare the Mitsubishi FX5U auxiliary-status mapping and standard Siemens S7-1200 diagnostic interface checks. These DQC examples keep ordinary PLC status separate from safety evaluation; they do not establish DQE/DA31 compatibility or add reset/EDM functions to a relay.