Siemens 505-6108-B 8-Channel Analog Input Module

Siemens PPX:505-6108-B is an eight-channel analog input module (8 AI) in the Series 505 PPX family, designed for TI 505-series PLC backplanes to digitize field signals for the controller. The module provides eight single-ended analog input channels intended for voltage or current signals and is identified by part number 505-6108-B; in Siemens catalog notation it is listed with WX 08 and WY 00 base addressing. As an analog current/voltage input module, it accepts standard field signals from sensors and transducers and feeds the measured values into the PLC for processing, monitoring, and control logic. The 8-channel configuration supports expanding an existing 505 system’s sensing capabilities without adding digital I/O or external signal conditioning, making it suitable for simple process monitoring, data logging, and alarm strategies that require real-time analog data. The B variant sits in the A/B family alongside the 505-6108-A, sharing core functionality and connection scheme, and is compatible with backplane networking used by Siemens’ older 505-series systems; for replacements or upgrades, a drop-in replacement such as CTI’s 2558 is noted in compatibility references as supporting 8-channel analog inputs compatible with 505-6108-A/B hardware.