Siemens 6ES7278-4BD32-0XB0 SIMATIC S7-1200 SM 1278 4xIO-Link Master PLC I/O Module

The Siemens 6ES7278-4BD32-0XB0 is a SIMATIC S7-1200 SM 1278 signal module with 4 IO-Link master ports, letting the CPU exchange configuration and diagnostic data with IO-Link sensors and actuators over the same backplane slot used by a standard digital I/O module. It runs from 20.4 to 28.8 V DC, draws 1 W typical, and is rated IP20.

Technical Specifications

Certifications & Standards

• CE
• CSA
• UL
• cULus
• FM
• RCM
• KC
• Marine

Selection Notes

Each of the 4 master ports on this module can be parameterized as an IO-Link port or fall back to standard digital I/O, so it fits either a full IO-Link sensor network or a mixed installation where only some devices support the protocol. Because it occupies one signal-module slot (45 mm wide) on the S7-1200 backplane, it replaces a standard SM without needing a separate CM communication slot, which matters on a compact CPU that supports only 6 module slots total. The 1 W typical power loss and IP20 rating keep it within the same panel-space and enclosure requirements as any other S7-1200 signal module, so no extra cooling or enclosure changes are needed when adding it to an existing rack.