[https://web.archive.org/web/20220621094412/https://www.aliexpress.com/item/3256804041357659.html PLC Input Module Terminal Block 4 6 Way/Channels Photoelectric Proximity Switch NPN PNP Sensor 3 Wires Conversion Transfer Board| | - AliExpress] (Wayback Machine) | [https://web.archive.org/web/20220621094412/https://www.aliexpress.com/item/3256804041357659.html PLC Input Module Terminal Block 4 6 Way/Channels Photoelectric Proximity Switch NPN PNP Sensor 3 Wires Conversion Transfer Board| | - AliExpress] (Wayback Machine) |