SIPLUS S7-300 SM 321-20-pin. -25...+70°C with conformal coating Conformity with EN 50155 T1 Cat 1 Class A/B based on 6ES7321-7BH01-0AB0 . Digital input, electrically isolated '16 DI, DC 24V, 1x 20-pin,' process interrupt, diagnostics, suitable for isochronous operation SIPLUS S7-300 SM 321-20-pin. -25...+70°C with conformal coating Conformity with EN 50155 T1 Cat 1 Class A/B based on 6ES7321-7BH01-0AB0 , Digital input, electrically isolated '16 DI, DC 24V, 1x 20-pin,' process interrupt, diagnostics, suitable for isochronous operation Operation SIPLUS S7-300 digital module input SM 321, DI 16xDC 24 V -25 ... +70 °C with conformal coating EN 50155 T1 Cat 1 Class A/B based on 6ES7321-7BH01-0AB0