The FESTO 2735960 CPX-FB37 is an industrial bus node for the CPX platform, developed for automation systems that require reliable field-level communication, compact installation, and stable diagnostic capability. This model uses the EtherCAT protocol and is intended to serve as the communication interface between a CPX modular terminal and the higher-level control system. Official FESTO technical data lists the product as CPX-FB37, part number 2735960, with dimensions of 50 × 107 × 50 mm, a product weight of 125 g, and a nominal operating voltage of 24 V DC.
In modern factory automation, communication quality is no longer a secondary issue. A fieldbus node is often the component that determines whether distributed valves, I/O modules, and peripheral functions can be integrated cleanly into the machine architecture. The CPX-FB37 is built for exactly that role. As an EtherCAT bus node, it supports fast and deterministic communication in systems where response time, diagnostics, and modular expansion matter. FESTO specifies a baud rate of 100 Mbit/s, along with maximum address capacity of 128 bytes for inputs and 128 bytes for outputs, making it suitable for demanding automation tasks where structured data exchange is essential.
Key Technical Data
| Item | Specification |
|---|---|
| Brand | FESTO |
| Part Number | 2735960 |
| Model | CPX-FB37 |
| Product Type | Bus node |
| Protocol | EtherCAT |
| Dimensions | 50 × 107 × 50 mm |
| Product Net Weight | 125 g |
| Nominal Operating Voltage | 24 V DC |
| Operating Voltage Range | 18 V DC to 30 V DC |
| Typical Internal Current Consumption | 100 mA |
| Baud Rate | 100 Mbit/s |
| Degree of Protection | IP65 / IP67 |
| Ambient Temperature | -5 °C to 50 °C |
| Storage Temperature | -20 °C to 70 °C |
| Fieldbus Interface | 2 × M12x1 4-pin D-coded sockets |
| Housing Material | PA-reinforced |
| Corrosion Resistance Class | CRC 1 |
| Max. Address Capacity Inputs | 128 byte |
| Max. Address Capacity Outputs | 128 byte |
All values above are taken from official FESTO product and datasheet sources.
Product Positioning and Function
The CPX-FB37 is not a generic communication accessory. It is part of FESTO’s CPX electrical terminal system, which is widely used to create modular automation assemblies that combine pneumatic valve control, electrical inputs and outputs, and distributed machine functions into a unified platform. Within that structure, the CPX-FB37 acts as the communication gateway for EtherCAT-based systems. FESTO also notes configuration support via ESI file, which is important for engineering integration in EtherCAT environments.
This matters because the efficiency of a machine is not determined only by actuators and controllers. It is also determined by how cleanly the communication layer is implemented. A poorly matched bus node can create integration delays, unstable communication, or weak diagnostics. The CPX-FB37 addresses those problems by combining network communication, parameterization support, and diagnostic functions in a compact housing. FESTO specifies channel-oriented and module-oriented diagnostics, undervoltage monitoring of modules, and diagnostic memory, all of which improve fault tracing and maintenance efficiency in real industrial operation.
Mechanical and Installation Advantages
One of the practical strengths of the CPX-FB37 is its compact physical format. With a size of 50 mm in width, 107 mm in length, and 50 mm in height, it fits neatly into modular machine assemblies where space is limited. Its 125 g weight is also significant. This is a lightweight communication module, which helps reduce installation load and makes it easier to integrate into compact cabinets, machine frames, or distributed automation stations. For OEM equipment builders and maintenance teams, a lighter and smaller bus node generally means more flexible layout planning and less mechanical burden on the installation structure.
The product uses two M12x1 4-pin D-coded sockets as the fieldbus interface. This is a standard industrial connection style for robust Ethernet-based communication, and it is suitable for environments where connection reliability matters. The CPX-FB37 also has IP65 and IP67 protection, which means it is designed for industrial conditions rather than clean-office electronics environments. That protection level supports use in factories where dust, splash exposure, and general workshop contamination are normal operating conditions.
Electrical Performance and System Compatibility
From an electrical perspective, the CPX-FB37 is designed for standard industrial 24 V control systems. FESTO lists a DC operating voltage range from 18 V to 30 V, with a nominal operating voltage of 24 V DC and typical internal current consumption of 100 mA. These values place it well within the standard range used in industrial automation, making integration more straightforward for machine builders already using common 24 V architectures.
FESTO also lists several communication and system-level functions that increase the value of this bus node in real-world use. These include acyclic data access via fieldbus, diagnostic object support, emergency message capability, variable PDO mapping, and system status mapping through process data. In addition, the datasheet notes a compatibility mode for the FB38, which can be useful in system migration or mixed-platform engineering scenarios. These details show that the CPX-FB37 is not a basic on/off communication interface. It is a fieldbus component intended for structured and scalable industrial communication.
Diagnostic and Service Value
A communication node becomes valuable when something goes wrong. That is where the CPX-FB37 is stronger than low-end alternatives. FESTO specifies both product-specific LEDs and bus-specific LEDs, including indicators for modify/parameterization, load supply, electronics supply/sensor supply, system fault, communication error, network active on port 1, network active on port 2, and run/communication status. This LED architecture helps operators and technicians identify communication and power conditions quickly during startup, commissioning, and troubleshooting.
The unit also includes DIL switch operator controls, which support local configuration handling. Combined with the internal diagnostic functions, that makes the CPX-FB37 a more maintenance-friendly component than simpler bus nodes that offer limited visibility into network or module condition. In practical terms, this can reduce downtime and shorten fault isolation time on site.
Material and Reliability Characteristics
The official FESTO datasheet lists the housing as PA-reinforced, and the product is marked as RoHS-compliant. It is also rated CRC 1, meaning low corrosion stress suitability. For standard industrial indoor environments, this is appropriate and consistent with the intended application class. FESTO’s reliability datasheet further lists an MTTF of 52.6 years, which indicates a design positioned for long-term industrial service when used as intended within specification.
Typical Application Areas
| Application Area | Why CPX-FB37 Fits |
|---|---|
| Automated assembly lines | Fast EtherCAT communication with modular I/O and valve systems |
| Packaging machinery | Compact size and strong diagnostics for distributed machine control |
| Material handling systems | Reliable field-level communication and status monitoring |
| Pneumatic control platforms | Native fit within FESTO CPX modular terminal architecture |
| General machine building | Standard 24 V DC design and industrial protection levels |
These applications are consistent with the CPX platform role and the official CPX documentation around modular electrical terminal use.
Conclusion
The FESTO 2735960 CPX-FB37 is a compact and technically capable EtherCAT bus node designed for the CPX modular automation platform. Its main strengths are clear: 125 g product weight, compact 50 × 107 × 50 mm dimensions, IP65/IP67 protection, 24 V DC nominal operation, robust diagnostic features, and structured support for modern EtherCAT communication. For machine builders, integrators, and maintenance teams working with FESTO CPX systems, this model is a practical choice when stable communication, diagnostic visibility, and installation efficiency are required.
