BECKHOFF CX51x0 Embedded PC Deployment Guide

BECKHOFF CX51x0 Embedded PC Full Integration and Fault Diagnosis Guide

Product positioning and system value

In the field of automation control, for small and medium-sized applications that are cost sensitive but require complete PC functionality and multi protocol fieldbus communication, traditional embedded controllers often have insufficient performance, while high-end industrial control computers suffer from resource waste. The Beckhoff CX51x0 series of embedded PCs precisely fills this gap - based on Intel Atom processors (single core E3815, dual core E3827, quad core E3845), it provides 2/4 GB DDR3 RAM, CFast card and microSD card dual storage slots, two independent Gigabit Ethernet ports, four USB 2.0 ports, and DVI-I display output. Its modular power terminal (on the right) can automatically recognize K-bus (bus terminal) or E-bus (EtherCAT terminal), and supports up to ten optional interfaces (RS232/422/485, EtherCAT master/slave, PROFIBUS, CANopen, PROFINET, etc.), making it an ideal platform for replacing old controllers.

This article is aimed at automation system integration and on-site maintenance engineers, focusing on the hardware selection, mechanical installation (including ATEX explosion-proof requirements), interface definition, power wiring and UL compliance, 1-second UPS persistent data protection, K-bus/E-bus diagnostic codes, TwinCAT configuration (network card redundancy, serial port, cable redundancy), BIOS settings, maintenance and battery replacement, and common troubleshooting of CX51x0, providing a complete set of engineering deployment and diagnostic guidelines.

Product model and hardware architecture

1.1 Model specifications

The CX51x0 series includes three models, with differences mainly in processor and memory:

Model: Processor, Core, Frequency, Memory Size (W × H × D), Weight

CX5120 Intel Atom E3815 1 1.46 GHz 2 GB DDR3 122×100×92 mm ~975 g

CX5130 Intel Atom E3827 2 1.75 GHz 4 GB DDR3 142×100×92 mm ~1095 g

CX5140 Intel Atom E3845 4 1.91 GHz 4 GB DDR3 142×100×92 mm ~1095 g

The basic configuration includes: CFast card slot (push out), microSD card slot (push out), two RJ45 Gigabit Ethernet ports (Intel i210 controller), four USB 2.0 Type A ports (each with a current limit of 500 mA), and a DVI-I interface (supporting analog VGA and digital DVI-D, and can be connected to a VGA display through an adapter). Built in 1-second UPS (supercapacitor), which can save up to 1 MB of persistent variables to the CFast card in case of power failure.

1.2 Optional interfaces (pre installed at the factory, cannot be added later)

Model suffix interface type description

N010 DVI-D second channel digital video output, supports cloning or expanding desktop, limited to CX5130/5140 only

N011 DisplayPort 1.1a version, up to 2560 x 1600@60Hz Synchronized transmission of audio and video

N020 audio with 3 3.5mm sockets: Line In, Mic In, Line Out (200 mW, suitable for headphones), not supported by Win CE 7

N030 RS232 9-pin D-Sub male head, maximum 115.2 kbaud, limited driver support (some APIs are missing)

N031 RS422/RS485 9-pin D-Sub female head, photoelectric isolation 500 V, default no echo+terminal resistance, optional other configurations factory settings

M112 EtherCAT main station dual RJ45, direct FPGA connection, full DC synchronization, supports cable redundancy

B110 EtherCAT Slave Dual RJ45, EtherCAT IN/OUT, 100 Mbaud

M310/B310 PROFIBUS master/slave 9-pin D-Sub, 9.6 kbaud~12 Mbaud

M510/B510 CANopen master/slave 9-pin D-Sub, 10 kbaud~1 Mbaud

M930/B930 PROFINET RT Dual RJ45 Switch, Controller or Device

Important: When using in the explosion-proof area (Zone 2), equipment modification parts CX2900-0107 (including connector fixing bracket and repositioned nameplate) must be ordered, and only USB/RJ45 plugs can be used and tied securely. Audio interface N020 cannot be used. At this point, the device must be installed in a casing that meets IP54 standards.

Mechanical installation and DIN rail fixation

2.1 Only allowed installation direction

CX51x0 must be installed horizontally with ventilation holes arranged vertically. Violating this rule will result in poor heat dissipation and shortened lifespan. Maintain at least 30mm of free space above and below.

Figure 19 (manual) shows the correct direction - cooling air flows vertically through the heat sink. Vertical installation or inversion in Figure 20 are prohibited.

If the vibration direction is parallel to the guide rail, an additional fixed bracket must be installed to prevent slippage.

2.2 Steps for hanging rails

Use TS35/7.5 or TS35/15 rails that comply with DIN EN 60715.

Use a screwdriver to move the locks at the top and bottom of the module to the unlocked position.

Hang the module onto the guide rail from the front and press down until you hear a "click" sound to lock it.

Reset the lock buckle (press it back to its original position).

2.3 Installation of microSD and CFast cards

Both types of card slots use the push push principle:

Disassembly: Gently push inward to eject the card by 2-3 mm (CFast is about 4 mm), and then pull it out.

Installation: Push in until you hear a meshing sound. After installation, the CFast card should be flush with the front surface of the housing; The microSD card should be about 1 mm lower than the housing.

Only use industrial grade memory cards provided by Beckhoff (wide temperature range, high write life). CFast order numbers: CX2900-0026 (20 GB) to CX2900-0044 (320 GB); microSD：CX1900-0122（512 MB）、CX1900-0132（16 GB）。

2.4 Passive EtherCAT Terminal Installation Prohibition

Passive EtherCAT terminals (such as EL9195) must not be directly installed on the right side of the power module. Passive terminals have no process mapping and do not consume E-bus current. If it is tightly attached to the power module, it will weaken the E-bus signal. Correct practice: Insert at least one active terminal (a common terminal that consumes E-bus current, such as a digital input module) between the power module and the passive terminal. Identification method in TwinCAT tree: Passive terminals do not display process data, and the value in the "E-bus (mA)" column is the same as the previous terminal.

Power wiring and UL requirements

3.1 Definition of Wiring Terminals

The power terminal is located on the right side and is spring crimped (wire 0.5-2.5 mm ², stripped 8-9 mm):

Us (upper row): "24 V" and "0 V" - power the CPU and K-bus/E-bus. This is the core power supply of the system.

Up (bottom row): "+", "-", and "±" - supply power to the power contacts of the bus terminals (electrically isolated from Us).

After power on, the two green LEDs should light up:

Us 24V LED: CPU and bus power supply are normal

Up 24V LED: Power contact supply is normal

3.2 Power supply capacity and fuses

Us needs to provide 24 V DC (-15%/+20%, i.e. 19.2~28.8 V), maximum power consumption: CX5120 11 W, CX5130 14 W, CX5140 16 W (an additional 7 W is added during charging). Recommend using a 4A slow fuse (UL248) or NEC Class 2 power supply.

The maximum load of the Up contact is 10 A, and a separate fuse not exceeding 10 A must be configured.

Important: Always disconnect the 24V line when cutting off the power, and do not disconnect the 0V (ground wire), otherwise it may cause backflow and damage the equipment through the shielding layer.

3.3 UL Compliance

The UL label of CX51x0 is on the nameplate. UL certification environmental requirements: The power supply voltage source is isolated 24 V DC, with a maximum 4 A fuse (UL248) or NEC Class 2. Two Class 2 power supplies must not be connected in series or parallel.

1-second UPS persistent variable protection

4.1 Principles and Limitations

The CX51x0 is equipped with an UltraCap, which can maintain processor power for several seconds after the main power supply drops, and is used to save persistent variables (VAR PERSISTENT) to the CFast card. The maximum safe storage capacity is 1 MB of data (covering the entire lifespan). Do not save K-bus/E-bus data as they may become invalid when power is lost.

SUPS can be enabled/disabled in BIOS (menu: Advanced>Power Controller Options). Default enabled. It also provides the "Hold USB" option (cutting off USB power in UPS mode to save energy) and a startup delay (Delay 0-255 seconds).

4.2 Configuration steps

BIOS confirms SUPS Enable=[Enable].

Windows write filter processing: The persistent data storage path is either WinCAT Boot (TC2) or WinCAT 3.1 Boot (TC3). If FBWF is enabled, ensure that the directory is in the exception list (added by default). EWF must be closed. UWF does not need to be closed, but exceptions need to be configured.

PLC declares persistent variables:

st

VAR PERSISTENT

counter : INT;

systemState : BOOL;

END_VAR

Loop call function block FB_S-UPS_CX51x0 (located in Tc_2SUPS library, requires TwinCAT v3.1 B4016 or above).

Input parameters

EUpsMod: Recommend eSUPs_WrPersistData_Shutdown (perform quick shutdown after saving data)

EPersistentMode: default SPDM2PASS (write twice, more reliable)

TRecoverTime: default T # 10s (waiting time for recovery after short-term power failure)

When the output bPowerFailed Detect is TRUE, it indicates a power failure. At this time, other applications should be stopped to save CPU time for saving data:

st

IF NOT FB_S_UPS_CX51x0.bPowerFailDetect THEN

//Running code normally

END_IF

Verify the validity of persistent data: In TC3, check the implicit variables PlcAppSystemInfo. BootDataLoaded (TRUE indicates successful loading) and OldBootData (TRUE indicates backup loaded). Read the 4th bit (persistent) and 0th bit (hold) of the SYSTEM INFOTYPE. bootDataMlags in TC2.

4.3 Common Problems

If the save is not successful, check the registry ClearInvalidPersistentData=0 (default backup used) or 1 (delete backup).

After replacing the CFast card, the persistent variable file (Port_85x. bootdata) is lost, and the first boot will load a backup (if present) or reset to its initial value.

Detailed interface description and special configuration

5.1 Ethernet interface (X000, X001)

Two independent gigabit ports, factory configured with TwinCAT real-time Ethernet (EtherCAT). LED: Left (LINK/ACT) - Green constant light indicates connection, flashing indicates data; Right (SPEED) - not lit=10 M, green=100 M, red=1000 M.

Jumbo Frame: Intel raw drivers need to be installed (which will overwrite Beckhoff real-time drivers), and then set the Jumbo Packet to 4088 or 9014 bytes in the Advanced tab of the Device Manager. Suitable for high throughput applications such as video streaming.

NIC Teaming: Intel raw drivers are also required. Create a new Team in the Teaming tab and select "Adapter Fault Tolerance" as the type to achieve redundancy. Note: These network ports should not be bound when using real-time EtherCAT.

Restore Beckhoff real-time driver: Run TcRteinstall.exe (TC3 path: C: TwinCAT 3.1 System ), select the interface and install it.

5.2 DVI-I（X200）

The maximum distance is 5 meters, supporting resolutions from 640 × 480 to 1920 × 1200. It can be converted to VGA (passive adapter) or connected to Beckhoff's DVI Extended remote panel (up to 50 meters away).

5.3 Optional Interface Special Configuration

RS232 (N030): Limited driver support, does not support APIs such as Setup Comm and AKS ommBreak. If all functions are required, consider using USB to serial port conversion.

RS422/485 (N031): default no echo+terminal resistance (endpoint). Other configurations (with echo, no terminal, RS422 full duplex) must be specified at the factory (ordering suffix such as N031-0001, etc.), and DIP switches cannot be configured on site.

EtherCAT Master Station (M112): Directly connected to FPGA, it can achieve three EtherCAT Master Stations (two front board ports+one through terminal side). Supports full DC synchronization without the need for external synchronization.

EtherCAT Slave (B110): Connect CX51x0 as a slave to the EtherCAT network.

PROFIBUS: Pin 3 (red line B) is RxD/TxD-P, and Pin 8 (green line A) is RxD/TxD-N. Pin 6 output+5V is used for active terminal resistors and must not be used for other purposes.

CANopen: Pin 2=CAN low, Pin 7=CAN high, Pin 3&6=GND, Pin 5=shielded.

5.4 Serial port usage mode under Windows 10

N030/N031 has two operating modes under Windows 10, which can be switched through BIOS:

Mode BIOS Settings (LPSS&SCC Devices Mode) OS Selection Effect

TwinCAT (default) PCI mode Windows 7 serial port is not visible in Windows Device Manager, recognized as COM99 in TwinCAT

Windows 10 ACPI mode Windows 8. x serial port displays as COM1 in Device Manager, TwinCAT cannot be used

After switching modes, a restart is required. Starting the PLC in TwinCAT mode will display an error (does not affect functionality).

Software and TwinCAT configuration

6.1 Selection of Operating System

CX51x0 supports OS and order code (5th digit in the model):

Windows Embedded Compact 7 (security updates have stopped, TwinCAT is only up to Build 4024)

Windows Embedded Standard 7 P (32/64 bit)

Windows 10 IoT Enterprise 2016/2019/2021 LTSB/LTSC (32/64 bit)

TwinCAT/BSD

Minimum capacity of CFast card: Windows CE 7 and TwinCAT/BSD require 20 GB; Windows 7/10 requires 40 GB.

6.2 TwinCAT Scanning and Configuration

Select target system: Click on "Choose Target" in TwinCAT and search by IP or hostname (default hostname format CX - followed by MAC address and three bytes). Login credentials: Administrator/1.

Scan I/O devices: right-click on "I/O Devices" ->Scan. Automatically recognize K-bus (displayed as CX-BK) or E-bus (displayed as EK1200).

Configure serial port (N03x): After scanning, a COM port appears under the device tree. Select "PCI/PCIe device" in the "Serial Port" tab, click Search to select the corresponding COM port. If the option is grayed out, try other options first before switching back.

Ethernet cable redundancy: Requires TS622x authorization (TC2) or TC3 built-in but requires authorization. In EtherCAT main station ->Advanced Settings ->Redundancy, select "Second adapter" and specify the second network port. When a disconnection occurs in a circular topology, communication automatically switches paths. View the status of "LINK_MIS A/B" information through the Online tab.

6.3 Hardware watchdog

Use the function block FB-PcWatchdog-BAPI (Tc2-System library). Set nWatchdogTimeS (e.g. 1 second), and then loop call (interval must be less than the set time). If the PLC stops or enters a dead loop, the watchdog will automatically restart the embedded PC. Note: During debugging (breakpoint, reset, stop TwinCAT), the watchdog should be disabled, otherwise it will restart unexpectedly.

Diagnose LED and K-bus/E-bus fault codes

7.1 Front panel LED

LED color/meaning

PWR green=power supply is normal; Red/Yellow (brief at startup)=Bootloader running

TC green=Run, red=Stop, blue=Config, yellow=TwinCAT 3 PLC crash/error

HDD red=CFast card access in progress

FB1/FB2 optional interface status (depending on fieldbus type)

7.2 Power terminal LED (K-bus mode)

Meaning of LED

Us 24V green=CPU and bus power supply are normal

Up 24V green=normal power supply to power contacts

K-BUS RUN green=K-bus communication is normal

K-BUS ERR red=error, flashing code

K-BUS ERR flicker decoding:

Quick flashing → Start

The first slow sequence pulse number=error code

Pause (LED off)

The second slow sequence pulse number=incorrect parameter (fault terminal position, excluding power terminal)

Common error codes (see page 80 of the manual for the complete table):

Error code parameter meaning handling

Continuous flashing - EMC interference check for power spikes, grounding, and filtering

30 K-bus command error: No terminal or damaged terminal; Binary search for faulty terminals

Immediately disconnect and check the first terminal and end KL9010 after the 40 power module

Check the (n+1) th terminal for wire breakage after the nth terminal

5. Communication error with the nth terminal register. Replace the nth terminal

6 0 initialization error, replace embedded PC

6 1/8 internal data error hardware reset (power off and restart)

7 0 Process Data Length Mismatch Check for Consistency between Configuration and Actual Terminals

The State variable (under TwinCAT bus coupler) provides more diagnostic bits:

Bit0: K-bus error

Bit1: Terminal configuration change

Bit2: Process image length mismatch

Bit8: No valid input

Bit9/10: Input/output update incomplete

Bit11: Watchdog

Bit15: Asynchronous reset activation

7.3 E-bus mode

Meaning of LED

Us/UP 24V as above

L/A off=E-bus not connected; Always on=Connected with no data; Flashing=Data transmission and reception in progress

E-bus error checked through TwinCAT CoE directory, no dedicated ERR LED.

Maintenance and battery replacement

8.1 Preventive replacement cycle

Suggested replacement interval for components

Motherboard battery (CR2032) 5 years

UPS/battery pack for 5 years

CFast, SSD, microSD 10 years

Fan (if any) for 5 years

8.2 Battery replacement steps

Turn off the embedded PC and disconnect the power.

Open the front flap.

Carefully remove the old battery (CR2032, 3V). Use insulated tools (if not accessible by fingers).

Push in the new battery with the negative pole facing left (pointing towards the DVI-I interface).

Close the cover and reset the date and time in BIOS after powering on again.

8.3 Cleaning

Clean only the outer shell using a soft damp cloth. Do not use compressed air (which may blow dust into the interior). You can use a vacuum cleaner to remove dust from the ventilation holes. Corrosive solvents, abrasives, and metal scrapers are prohibited.

Practical troubleshooting of common faults

Possible causes and solutions for the fault phenomenon

After power on, the PWR LED does not light up. 24 V power supply is missing or the polarity is reversed. Measure the voltage of the Us terminal at 19.2~28.8 V; check the fuse (4 A)

The PWR is on but the TC LED is off. TwinCAT is not running or the configuration is missing scanning I/O devices; Check the connection of the target system; Restart TwinCAT Runtime

K-BUS ERR continuously flashes EMC interference or historical errors not cleared. Check the grounding and power filter; Disconnect Us and then power on to clear the status

Unable to save persistent variables. Write filter not configured with exceptions or registry settings incorrect. Check FBWF exception directory WinCAT Boot; Set ClearInvalidPersistentData=0

Serial port cannot find BIOS mode error in TwinCAT (should be PCI mode) Enter BIOS Advanced>LPSS&SCC Configuration set to PCI mode, OS Selection set to Windows 7

Ethernet cable redundancy does not work, TS622x authorization is not installed, or the second adapter is not configured with installation authorization; Select the second network port correctly in Advanced Settings>Redundancy

System time: Every time the system is shut down, reset the motherboard battery and replace the CR2032 battery when it runs out

After vertical installation, if the CPU temperature is too high and violates the installation direction (vertical is prohibited), it should be installed horizontally and ensure a ventilation distance of 30mm

Passive EtherCAT terminal causes communication interruption. The passive terminal is directly attached to the power module and the active terminal (such as EL1004) is inserted in the middle

Remote Display Cannot Connect (Windows CE) Remote Display is not enabled. Set Remote Display to On through Beckhoff Device Manager>Boot Opt

Retirement and disposal

Software shutdown: Normal shutdown of the operating system and TwinCAT.

Power off: Cut off the 24V power supply and unplug all wiring (first Us/UP, then signal line).

Remove the DIN rail: Use a screwdriver to open the upper and lower locks, pull the orange strap, and lift the module upwards to detach from the rail.

Separate modules: If there are multiple module combinations, separate them according to the above method.

Environmental disposal: Electronic components must comply with local electronic waste regulations (such as WEEE) and must not be mixed with household waste.