System Overview

System Overview 1:

The system

The CX5000 series devices are DIN rail-mountable, fanless Embedded PCs with direct connection for Beckhoff Bus Terminals or EtherCAT terminals. In contrast to the other CX device families, the CX5000 series has a fixed, non-expandable number of system interfaces. The housing design for this series is optimised for robustness and compactness. No modular expandability for the left-hand side is provided. Although EtherCAT integration offers a wide range of expansion capability. Further master/slave fieldbus connections (PROFIBUS, CANopen, DeviceNet) or communication interfaces (RS232, RS422/RS485) and all other signal types accessible via EtherCAT can be directly connected as EtherCAT Terminals. Two independent Gigabit Ethernet ports and four USB 2.0 interfaces are available. A Beckhoff control panel or a commercially available DVI monitor can be connected to the DVI D interface. A serial port (RS232/RS422/RS485) or a fieldbus connection with master or slave function can be added as an optional interface as required. An interchangeable Compact Flash card located behind a flap that is accessible from outside is used as boot and storage medium. The built-in capacitive 1-second UPS ensures secure backup of persistent application data on the Compact Flash card. The date and time are buffered via a replaceable battery. The operating system can be Windows CE or Windows Embedded Standard. The TwinCAT automation software transforms a CX5000 system into a powerful PLC and motion control system that can be operated with or without visualisation.

EtherCAT as a fast I/O system

Like all Embedded PCs from the CX series (except CX100x), the CX5000 was developed for optimum interaction with EtherCAT. One of the two independent Ethernet interfaces of the CPU module (X001) is intended for EtherCAT mode. The primary EtherCAT connection is generally established via terminals. Both can also be configured as a ring in order to achieve line redundancy.

Interestingly, EtherCAT offers several options for connecting conventional fieldbus systems to the CX50x0:
As EtherCAT device in terminal form, for example the PROFIBUS master as EtherCAT Terminal EL6731. In practice, this means that the PROFIBUS master can be positioned exactly where it is required within a machine. It no longer has to be implemented as a plug-in card in the IPC or a master controller in the control cabinet.

PLC, Motion Control and visualisation

As a DIN rail IPC and in conjunction with the TwinCAT software from Beckhoff, the CX50x0 offers the same functionality as large Industrial PCs. In terms of PLC, up to four virtual IEC 61131 CPUs can be programmed with up to four tasks each, with a minimum cycle time of 50 μs. All IEC 61131-3 languages can be used.

Moreover, functionalities are available for Motion Control applications, such as simple point-to-point movements.

In addition to real-time execution of control tasks, the TwinCAT real-time kernel ensures that enough time remains for the user interface (HMI), to communicate with the real-time components via software interfaces such as ADS or OPC.

For CX50x0 the familiar basic principle applies: it is a programming tool for all controllers.
The complete programming of PLC, Motion Control and visualization is transferable to all PC controls from Beckhoff, which is reassuring in cases where it becomes apparent during a project that more processing power is required after all. In this case a system with higher performance can be used.

Fieldbus interfaces

The fieldbus interfaces are currently available as master and slave versions for the following fieldbuses:

Optional interfaces:

The optional interfaces can be used to connect single-channel fieldbus interfaces. Operation is limited to one interface at a time. If several fieldbus interfaces are required, they can be added as E-bus terminals (EL67xx). The following fieldbus interfaces are available:

The software

In combination with the TwinCAT automation software, the CX50x0 Industrial PC becomes a powerful IEC 61131-3 PLC with up to four user tasks. Additionally, Motion Control tasks can also be executed. Depending on the required cycle time, several servo axes can be controlled. Even special functions such as flying saw, electronic gearbox and cam plate can be realised.

The CX50x0 system is programmed in the same way as other bus controllers:

Remote programming via Ethernet

This option is used if the basic unit is equipped with “Windows CE.NET”. In this case, the system is programmed via a laptop or a desktop PC, which is connected to the CX via Ethernet (network or crossover cable). The programs are developed on the laptop with a standard TwinCAT software licence and then loaded into the target device.

Visualisation

The Beckhoff OPC server is available for interfacing with SCADA packets, if the two operating system variants “Windows CE.NET” or “Windows XP Embedded” are used. In other words, the CX50x0 also offers straightforward visualisation and simultaneous control in real-time on a single system.