expansion module: warranty : 2 years; binary input, connected to common potential: 0.0; binary input, not connected to common potential: 0. 0; Ethernet electrical ETH-BA-2E L: 0; Ethernet optical ETH-BB-2FO: 0; front design: standard; high-speed relay, NO contact: 0.0; housing type: flush mounting; interface USART-AB-1EL: 0 ; interface USART-AC-2EL: 0 ; interface USART-AD-1FO: 0 ; interface USART-AE-2FO: 0