6ES7221-3AD30-0XB0 Signal Board SB 1221, 4 DI 5VDC 200KHz SIMATIC S7-1200, Digital input SB 1221, 4 DI, 5V DC 200kHz, Sourcing input
6ES7221-3BD30-0XB0 Signal Board SB 1221, 4 DI 24VDC 200KHz SIMATIC S7-1200, Digital input SB 1221, 4 DI, 24 V DC 200 kHz, Sourcing input