Available. The Siemens 6ES5421-8MA11 is a digital input module from the SIMATIC S5 series, designed for industrial automation systems. This module features eight non-floating digital input channels, each operating at 24 V DC, suitable for various applications requiring precise digital control. It is compatible with S5-90U, S5-95U, and S5-100U PLCs, as well as ET 100U and ET 200U systems. The module has been discontinued and is no longer available for purchase. For existing infrastructures, repair services are available to extend its usability. Extending the lifespan of this module through repairs supports sustainability and cost-efficiency.