6 fail-safe analog inputs, SIL 3, end-of-life
The Siemens 6ES7336-4GE00-0AB0 is an SM 336 F-AI fail-safe analog input module for the S7-300 system, providing 6 channels for current measurement from 2-wire or 4-wire transducers in the 4-20 mA and 0-20 mA ranges. Rated SIL 3 per IEC 61508 and Category 4 per EN 954-1, this module is designed for safety-critical process monitoring where a fault must be detected and the system brought to a safe state.
Input specs and integration timing
Each of the 6 analog inputs has a typical input resistance of 150 ohms (max. 175 ohms) for both the 0-20 mA and 4-20 mA ranges. Resolution is 16 bits (15 bits + sign) with overrange, and the integration time is 20 ms at 50 Hz or 16.7 ms at 60 Hz — matching the line frequency to reject mains hum. The module draws 150 mA typical from the 24 VDC supply and up to 90 mA from the 5 V backplane bus. Power dissipation is 4.5 W typical.
Safety diagnostics and channel isolation
Diagnostic alarm and diagnostic information are readable; a group error SF (red) LED signals a fault. Fail-safe operation means the module can detect internal and external faults and report them. Channel-to-channel isolation, channel-to-backplane bus isolation, and channel-to-electronics-power-supply isolation are all provided. Isolation is tested at 370 V for 1 minute. Reverse polarity protection on the 24 VDC supply is included. The module requires a 20-pin front connector (ordered separately).
No official successor order code from Siemens is on record for this module. For a new design, consider the current-generation fail-safe analog input modules in the S7-1500F or ET 200SP F system — but those require a different backplane and engineering environment.