Q: How to choose the output mode of a safety light curtain?
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- Issue Time
- Jul 8,2025
A:
The output mode (Output Type) of the safety light curtain mainly depends on your equipment control system requirements and safety level design requirements. The following are selection suggestions:
| Application Scenario | Recommended output mode | Reason |
|---|---|---|
| General industrial automation system | PNP / OSSD | Quick response and strong compatibility |
| Japanese or old PLC control system | NPN | Matching control input type |
| Controlling high power devices (motors/contactors) | Relay output | Dry contacts are safer and can isolate high voltage |
| Requires a high safety level (such as PL e or SIL3) | OSSD (dual channel PNP) | Redundancy + self-test, meeting ISO 13849-1 standard |
| Use multiple light curtains in series and require intelligent control | OSSD + IO-Link | Remote diagnosis and parameter configuration |
Additional suggestions:
· Confirm the input type of the PLC or control system (NPN/PNP/dry contact);
· Confirm whether the safety function level (such as SIL/PL) needs to be met;
· If the supporting equipment requires high-frequency start-stop control, OSSD or PNP solid-state output is recommended;
· If it is used for old equipment or electrical isolation is required, it is safer to use relay output.