Do the Safety Door Switches and Safety Limit Switches have the polarity when used with direct current?
No, they do not have any polarity.
For Safety Light Curtain Robust & Basic New Lineup. Understanding the Indicators at a Glance.
Compact (104.5 mm), lightweight (1.3 kg) and easy-to-install Safety Laser Scanner
Supports ISO 13849-1 (PLe/Safety Category 4). Can be used on higher risk level applications by connecting to Safety Controllers.