Electrical and physical fit
The 6ES7 321-1BH02-0AA0: Each input is rated for a signal "1" voltage of 13 to 30 V DC, with a typical current draw of 7 mA. The permissible input voltage range is 20.4 to 28.8 V DC. Input delay is fixed (non-parameterizable) at 1.2 ms minimum and 4.8 ms maximum for both off-to-on and on-to-off transitions. Isolation between channels and the backplane is tested at 500 V DC via optocoupler. Cable length is limited to 1 000 m shielded or 600 m unshielded. The module supports 2-wire sensors with a permissible quiescent current up to 1.5 mA. Status indication per channel is provided by a green LED.