CPU 416-2 for S7-400 racks
The Siemens 6ES7416-2XK02-0AB0 is a CPU 416-2 for the S7-400 platform, carrying 64 KB work memory that is not expandable. It handles 244 bytes each of process input and output images, enough for mid-sized distributed I/O configurations on a single rack or across a PROFIBUS DP network via an external CP. Two integrated interfaces are on board: one MPI port and one RS 485 port, both isolated. The MPI supports up to 64 connections total, with one reserved for PG/OP, and S7 routing is active when the interface is enabled. The RS 485 port can be used for point-to-point communication or as a PROFIBUS DP master with the appropriate CP. Programming is done in STEP 7, supporting LAD, FBD, STL, SCL, CFC, GRAPH, and HiGraph. The CPU also supports forcing, single-step operation, and SYNC/FREEZE functions for deterministic process control.
Memory and timing constraints
Work memory is fixed at 64 KB with no expansion option. The CPU includes 8 counters with preset retentivity set to no retentivity by default. Timing resolution is 1 ms, with a lower cycle time limit of 10 ms. Communication connections are limited: 10 via CP, 64 via CP LAN, and 64 via CP PtP, all constrained by slot count and connection limits. The FM capacity is 64, also limited by slots and connections.
The module is 25 mm wide, 290 mm high, and 219 mm deep — a single-wide S7-400 slot. It mounts on a standard S7-400 rack and connects to the backplane bus. No special DIN-rail adapter is needed; it snaps into the rack slot. For distributed I/O, up to 4 IM 467 interfaces can be added via the rack. Ethernet connectivity requires a CP module and a loadable FB. The CPU can act as both a Modbus TCP client and server via the CP.