SIMATIC S7-400, digital input SM 421, isolated 16 DI, 24 V DC with 0.05 ms input delay alarm, diagnostics.
6ES7421-7BH01-0AB0 – SIMATIC S7-400, Digital input SM 421, 16 DI, 24 V DC with 0.05 ms input delay alarm
SIMATIC S7-400, digital input SM 421, isolated 16 DI, 24 V DC with 0.05 ms input delay alarm, diagnostics