PLC module SIMATIC S7 1200 Digital input SM 1221 16 DI 24 V DC Sink/Source 6ES72211BH320XB0 6ES7221 1BH32 0XB0|Motor Controller| - AliExpress
siemens s7-1200 sm 1221 dc 6es7221-1bh32-0xb0 | eBay
6ES7221-1BH32-0XB0 Siemens | Siemens PLC I/O Module for use with SIMATIC S7-1200 Series, 100 x 45 x 75 mm, Digital, SM 1221, 24 V dc, SIMATIC | 787-7945 | RS Components