Product Overview
The WAGO 750-628 Bus Extension Coupler Module is a specialized fieldbus interface unit within the versatile WAGO-I/O-SYSTEM, designed to function as a remote node on an INTERBUS network. This module serves as the critical communication gateway, connecting a local group of WAGO digital, analog, and special function I/O modules to a central INTERBUS master controller, such as a PLC. The primary role of the 750-628 is to manage all data exchange between the connected field devices (sensors and actuators) and the higher-level control system over the high-speed, deterministic INTERBUS fieldbus. It acts as an intelligent interpreter, reading input data from the I/O modules, packaging it into the INTERBUS telegram, and receiving output commands from the master to write to the appropriate output channels. As a bus extension coupler, it allows for the creation of distributed I/O stations that can be located close to the machinery they control, significantly reducing long and costly field wiring runs back to the central control cabinet. The WAGO 750-628 is renowned for its reliability and ease of configuration, automatically recognizing all connected I/O modules via its built-in microcontroller and assigning addresses accordingly. This plug-and-play functionality, combined with the mechanical robustness of the WAGO CAGE CLAMP® connection technology, makes the 750-628 Bus Extension Coupler a cornerstone for building flexible, scalable, and maintainable automation architectures in a wide range of industrial applications utilizing the INTERBUS protocol.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 750-628 |
| Manufacturer | WAGO Kontakttechnik GmbH & Co. KG |
| Product Type | Fieldbus Coupler / Bus Extension Coupler |
| Fieldbus System | INTERBUS |
| I/O-SYSTEM | WAGO-I/O-SYSTEM 750 Series |
| Data Transfer Rate | 500 kbit/s (standard INTERBUS speed) |
| Number of Connected Modules | Up to 64 I/O modules (limited by overall process image size) |
| Address Assignment | Automatic via K-bus (WAGO’s internal bus) |
| Internal Supply | Provides 5V DC to connected I/O modules via the backplane |
| External Supply | 24V DC (typically) for field sensors/actuators, connected via separate terminals |
| Connection Technology | Screwless CAGE CLAMP® for field wiring |
| INTERBUS Interface | 2 x SUB-D 9-pin female connectors (IN/OUT) |
| Diagnostics | LEDs for power, bus activity, and error status |
| Operating Voltage | 24V DC (typically, for coupler logic) |
| Operating Temperature | 0°C to +55°C |
| Mounting | On 35 mm DIN rail |
| Protocol Compliance | INTERBUS according to IEC 61158 |
Main Features and Advantages
Automatic configuration and diagnostics: A defining advantage of the WAGO 750-628 is its automatic node recognition and configuration. Upon power-up, the coupler’s internal microcontroller automatically scans the connected I/O modules on its internal K-bus, identifies their type and function, and builds the local process image. This data is then seamlessly integrated into the overall INTERBUS network configuration by the master’s configuration tool. This eliminates manual dip-switch settings and complex addressing, drastically reducing commissioning time and potential for error. The module also provides comprehensive diagnostic information via its status LEDs (power, bus activity, error) and communicates detailed fault data (e.g., module failure, short-circuit) back to the INTERBUS master, enabling rapid system troubleshooting and maintenance.
