Failsafe input module for S7F systems
The Siemens 6ES7326-1BK00-0AB0 is a SM 326 failsafe digital input module for SIMATIC S7F systems, providing 24 failsafe inputs at 24 V DC with diagnostic interrupt capability. It is rated SIL 3 per IEC 61508 and Cat. 4 per EN 954-1, making it suitable for safety applications up to the highest performance level without a separate safety relay.
Input characteristics and wiring
Each input draws a typical 10 mA at signal "1" (11 to 30 V), with a signal "0" threshold of -30 to +5 V. The module accepts 2-wire proximity sensors when the short-circuit test is deactivated, with a permissible quiescent current up to 2 mA. Input filtering is symmetric: 3.4 ms max for both 0-to-1 and 1-to-0 transitions. Maximum cable length is 200 m shielded, 100 m unshielded. The module requires a 40-pin front connector (sold separately) and draws up to 450 mA from the load voltage L+ (without load) plus 100 mA from the backplane bus at 5 V DC. Typical power loss is 10 W.
Physical dimensions and environment
Ambient temperature range is up to 60 °C. Isolation is tested at 500 V DC / 350 V AC between channels and backplane bus, with channel-to-channel isolation in groups of 12.