CPU 414-4H for fault-tolerant S7-400H systems
The Siemens 6ES7414-4HM14-0AB0 is a CPU 414-4H designed for the S7-400H fault-tolerant automation platform. Its FM (fault-tolerant mode) is limited by the number of slots and connections in the rack, per the system manual — this is the governing constraint for redundancy configuration, not a raw I/O count. It supports up to 4096 digital inputs and 4096 digital outputs, with 8 counters preset at 120 kHz. That I/O capacity suits medium-to-large redundant process or manufacturing lines where uptime is critical. Programming languages include LAD, FBD, STL, SCL, CFC, GRAPH, and HiGraph. System function blocks for RDREC, WRREC, RDSYSST, and others are available.
Communication and integration
MPI is supported with a maximum cycle time of 200 ms. RS 485 is available for point-to-point or multi-drop links. The CPU can act as both Modbus client and server via CP modules (PtP or CP 340/341), with up to 10 connections via CP. Routing is enabled, so the CPU can forward messages between subnets. Dimensions: 50 mm wide, 290 mm high, 219 mm deep. The CPU is isolated and includes retentive data memory.