What this CPU delivers
The 6AG1518-4FP00-4AB0 is a fail-safe CPU in the S7-1500 line, built for safety applications requiring PROFIsafe communication at V2.4 or V2.6. It processes both standard and fail-safe logic, supporting FBD and LAD with failsafe blocks, and includes a dedicated ERROR LED and MAINT LED for diagnostics. Rated for ambient temperatures from -40 °C to 70 °C, this CPU fits enclosures outside conditioned spaces — cold storage, desert installations, or unheated cabinets — without forced derating.
Integration and I/O profile
The process image handles up to 32 kbyte each for inputs and outputs, covering all I/O in the image. The CPU supports up to 8 additional communication modules (PROFIBUS, PROFINET, Ethernet) via the left-side slot. RS-485 is available on the X4 interface for legacy serial devices. Programming can be in LAD, FBD (both with failsafe), STL, SCL, or GRAPH. The integrated and controllers handle temperature loops and valve actuation directly, reducing the need for external controllers. Physical footprint: 175 mm wide, 147 mm high, 129 mm deep — standard S7-1500 format, so it fits existing panel layouts designed for the 1518 series. The hardware clock keeps real-time sync without an external module.