Redundant CPU with 4 MB program memory and five PROFINET ports
The Siemens 6ES7517-4HQ10-0AB0 is a CPU 1517H-4 PN central processing unit for the S7-1500H redundant system, carrying 4 MB of work memory for program code and 50 MB for data — enough headroom for large batch recipes or multi-axis coordinated motion sequences without memory fragmentation. Five PROFINET ports are split across three interfaces: the first two are RT-capable with integrated 2-port switches, the third is a dedicated PROFINET interface, and the fourth and fifth are H-SYNC links that synchronise the redundant CPUs for bumpless failover on a line fault. A SIMATIC Memory Card is required for operation — the CPU has no onboard load memory, so the card holds the project, firmware, and recipe data.
Active lifecycle — no end-of-life horizon
Export control is straightforward: AL:N / ECCN:EAR99H means no special license is required for most commercial destinations. RoHS compliance is confirmed effective 24-01-25, and REACH Article 33 candidate-list information is available on request.
Integration into a redundant control cabinet
The CPU mounts on a standard S7-1500 U-rail (DIN rail) in the control cabinet — the 25.6 x 20.6 x 17.5 cm package dimensions fit a standard 800 mm-wide enclosure with room for power supplies and I/O. For a redundant pair, two CPUs plus synchronisation modules and fibre-optic H-SYNC cables occupy roughly 6 to 8 slots on the rail; plan the backplane bus terminator placement accordingly. The product group code 4B91 and group code R132 are internal Siemens classification fields used for spare-parts cross-referencing and warranty returns — include them on the PO line if your ERP requires them.