What This Module Delivers
The Siemens 6ED1055-1MB00-0BA2 is a LOGO! DM8 12/24R expansion module — 4 digital inputs plus 4 relay outputs, powered from a 10.8 V to 28.8 V DC supply. For a controls integrator, that means 4 discrete input channels and 4 relay-driven output channels added to a LOGO! 8 base controller without pulling a separate power rail. The relay outputs are rated 5 A on resistive loads and 3 A on inductive loads — enough for direct switching of small contactors, solenoid valves, or indicator lamps up to 1 000 W. The 1.5 ms transition time on both edges keeps the I/O map predictable for time-sensitive sequences.
Depth is 58 mm, height 90 mm — fits standard shallow enclosures. IP20 means it belongs inside a locked cabinet, not on the machine frame. The ambient range is 0 °C to 55 °C; for firmware ES03 and higher the cold end extends to -20 °C, which matters for unheated electrical rooms in winter climates. Input thresholds are TTL-compatible: signal "0" below 5 V DC, signal "1" above 8.5 V DC, with a typical 1.5 mA draw at the "1" state. The quiescent current at "0" must stay under 0.88 mA — a spec to check when sharing a sensor supply with other modules.
Approvals include CE (for the European market), UL and CSA (North American panel acceptance), FM (for industrial machinery), and marine certification — so it passes inspection on a shipboard panel or a factory floor with equal standing. Developed in accordance with IEC 61131, and rated limit class B for residential-area interference limits.