Introduction: The positioning of CX20x0 series in high-end control
The Beckhoff CX20x0 series embedded controller represents the high-performance benchmark for DIN rail mounted industrial PCs. This series includes three models: CX2020 (1.4 GHz single core Celeron), CX2030 (1.5 GHz dual core Core i7), and CX2040 (2.1 GHz quad core Core i7 with active fan). They not only have the compactness of traditional PLCs, but also the computing power of industrial PCs, supporting TwinCAT 2 and TwinCAT 3 real-time environments, and can achieve complex tasks such as PLC, motion control (up to 256 axes), CNC interpolation, and HMI visualization. Unlike the EL41xx analog terminal (I/O layer) and CP77xx panel PC (HMI layer) previously introduced, CX20x0 is located in the control core layer, and its hardware reliability directly determines the stability of the entire automation system. This article is based on the official hardware manual, systematically reviewing the mechanical installation, power and interface wiring, maintenance process of core replaceable components (CFast card, battery, fan), EtherCAT redundant configuration, LED status diagnosis, and common troubleshooting methods of CX20x0, providing a practical manual for on-site service and operation engineers.
Mechanical installation and heat dissipation requirements
2.1 DIN rail installation and dimensions
The basic module size of CX20x0 is 144 mm (width) x 100 mm (height) x 91 mm (depth), and the weight is approximately 1160~1230 g (depending on the model). Its casing is designed for a 35 mm standard DIN rail (compliant with EN 60715). When installing, hook the buckle on the module onto the upper edge of the guide rail, and then press down until you hear a "click" sound, indicating that it is locked in place. It is strictly prohibited to use brute force to avoid damaging the buckle.
This series adopts a modular design, and the basic CPU module must be connected to the CX2100 series power module on the right side (providing 24V power supply and I/O bus interface). The left side can be expanded with up to four system interface modules (such as RS232, RS422/485, EtherCAT slave, PROFIBUS, etc.) through a multi pin connector. Specialized top/bottom locking strips (Bar Clips) can be used to reinforce between modules to withstand vibrations and impacts. When disassembling, first remove the entire module from the guide rail, and then lift the locking strip with a screwdriver to separate each module.
2.2 Key installation locations and ventilation
The CX2040 is equipped with a fan with ball bearings and speed monitoring due to its quad core high power consumption (up to 42W), while the CX2020/CX2030 has no fan passive cooling at all. Regardless of the model, the correct installation direction is crucial: it must be installed horizontally (with the guide rail level), and a ventilation gap of at least 30mm must be maintained above and below the equipment. Because the heat dissipation holes are located at the top and bottom of the casing, hot air needs to naturally circulate vertically upwards. It is strictly prohibited to install it vertically (sideways) or upside down, otherwise it may cause the CPU to overheat, reduce frequency, or even shut down. The allowable temperature range for the environment is 0-60 ℃, the storage temperature is -40~+85 ℃, and the relative humidity is ≤ 95% (no condensation).
Power supply and wiring specifications
3.1 Power module selection and wiring
There are three variants of CX2100 power module:
CX2100-0004: Standard model with E-bus/K-bus automatic switching, no UPS.
CX2100-0904: Integrated capacitive UPS, capable of short-term buffering in case of power failure.
CX2100-0914: Integrated external battery pack charging management, supporting long-term UPS.
The power input terminal is a spring type terminal block, labeled with "24V" and "0V". The power supply requirement is 24V DC (-15%/+20%), which means the allowable range is 20.4V~28.8V. To ensure stable operation of the entire system (CPU+connected I/O terminal block), the power supply should provide at least 4A output capability.
Wiring steps: Use a screwdriver or push rod to press into the square hole to open the spring. Insert a wire with a stripping length of 8-9 mm (0.5-2.5 mm ²/AWG20-14) into the circular hole, and release the spring to complete the connection.
3.2 Grounding and power-off sequence
PE power contact: must be at the same potential as 0V (connected inside the control cabinet) and comply with EN 60204-1 PELV requirements - one end of the circuit must be grounded.
When cutting off power, be sure to disconnect the "24V" line first, and then disconnect the "0V" line, otherwise it may damage the equipment due to the formation of a current loop by the shielding layer. If an independently powered device (such as a touch screen) is connected externally, it must be ensured that its PE and GND are at the same potential as the CX system.

Core storage and battery maintenance
4.1 CFast Card Replacement (Operating System and Program Storage)