Siemens 6ES7960-1AA06-0XA0 Synchronization Submodule

Siemens 6ES7960-1AA06-0XA0 Synchronization Submodule is a SIMATIC S7-400H accessory that provides deterministic, bit-for-bit timing alignment between two CPU front panels via fiber-optic patch links. Designed for patch cables up to 10 meters, it plugs into the S7-400H synchronization network to maintain synchronized operation across CPUs in multi-rack installations, a critical requirement in high-availability control systems. The module is a compact 14 x 13 x 58 mm device and is documented by Siemens as the local-coupling variant (black) 6ES7960-1AA06-0XA0, with the remote-coupling counterpart 6ES7960-1AB06-0XA0 available for alternate topologies. In typical PCS7/S7-400H configurations, two sync modules—one per rack—are connected by two fiber-optic cables to achieve the necessary synchronization; longer cables can marginally affect cycle times. This part is specifically referenced in Siemens documentation as part of the synchronization module family used to link CPUs via patch cables in S7-400H systems.