Beckhoff: TwinCAT 2 (TX1270 Series)
The Windows Control and Automation Technology
The Beckhoff TwinCAT software system turns almost any compatible PC into a real-time controller with a multi-PLC system, NC axis control, programming environment and operating station. TwinCAT replaces conventional PLC and NC/CNC controllers as well as operating devices with:
open, compatible PC hardware
embedded IEC 61131-3 software PLC, software NC and software CNC in Windows NT/2000/XP/Vista, Windows 7, NT/ XP Embedded, CE
programming and run-time systems optionally together on one PC or separated
connection to all common fieldbuses
PC interfaces support
data communication with user interfaces and other programs by means of open Microsoft standards (OPC, OCX, DLL, etc.)
TwinCAT consists of run-time systems that execute control programs in real-time and the development environments for programming, diagnostics and configuration. Any Windows programs, for instance visualization programs or Office programs, can access TwinCAT data via Microsoft interfaces, or can execute commands.
A practically oriented software solution
TwinCAT offers a precise time base in which programs are executed with the highest deterministic features, independently of other processor tasks. The real-time load on a PC is set with TwinCAT; defined operating behavior is achieved in this way. TwinCAT indicates the system load for programs that are running. A load threshold can be set in order to assure a defined computing capacity for the operating programs as well as for Windows NT/2000/XP/Vista or Windows 7. If this threshold is exceeded, a system message is generated.
TwinCAT supports system diagnosis
The general use of hardware and software from the open PC world requires some checking: Unsuitable components can upset the PC system. Beckhoff has integrated a practical indicator of the real-time jitter, giving administrators an easy way to evaluate the hardware and software. A system message during operation can draw attention to incorrect states.
Depending on the setting, TwinCAT is started and stopped manually or automatically. Since TwinCAT is integrated into Windows NT/2000/XP/Vista and Windows 7 as a service, an operator is not needed to start the system: switching on is enough.
Restarting and data backup
When a program is started or restarted, TwinCAT loads programs and remanent data. To backup data and to shut down Windows NT/2000/XP/Vista and Windows 7 correctly, a UPS (uninterruptible power supply) is of great value.
TwinCAT and “Blue Screen”
The TwinCAT system can be configured such that real-time capability is maintained in the event of a BSOD (Blue Screen of Death) operating system crash. Real-time tasks such as PLC and NC can therefore continue to run and bring the controlled process into a safe state. Ultimately, it is the decision of the programmer whether or not to utilize this feature, bearing in mind that data or programs may already have been destroyed by the BSOD.
World-wide connection through message routing – “remote” connection is inherent to the system
According to the requirement for operating resources, the TwinCAT software devices can be distributed: TwinCAT PLC programs can run on the PCs or on Beckhoff Bus Terminal Controllers. A “message router” manages and distributes all the messages, both in the system and via TCP/IP connections. PC systems can be connected with each other via TCP/IP; Bus Terminal Controllers are integrated via serial interfaces and fieldbuses (EtherCAT, Lightbus, PROFIBUS DP, CANopen, RS232, RS485, Ethernet TCP/IP).
Since standard TCP/IP services of NT/2000/XP/Vista/CE and Windows 7 can be used, this data can be exchanged across the world. The system offers scalable communication capacity and timeout periods for the supervision of communications. OPC provides a standardized means for accessing many different SCADA/MES/ERP packets.
Complex tasks – new solutions
TwinCAT CNC offers complete CNC functionality as a pure PC-based software solution. TwinCAT CNC covers the complete range of classic CNC path control, including high-end systems for complex motion and kinematics requirements. The powerful, continuously evolving PC platform and the hard real-time base of the TwinCAT real time kernel provide the foundation for the CNC software.
TwinCAT CNC is based on TwinCAT PLC, the IEC 61131-3 software PLC. If TwinCAT NC PTP is used as the basis; powerful motion functionality for positioning tasks is also available. Parts programming is carried out according to DIN 66025 using high-level language extensions. TwinCAT CNC expanded TwinCAT NC I with classic CNC features. Up to 64 interpolating axes and comprehensive coordinate and kinematic transformations are possible.
Open for I/O and drive systems
In the CNC world, TwinCAT CNC offers unique openness towards the I/O periphery and the drive system through the consistent utilization of Fieldbus technology. A variety of I/O modules can be connected via all common fieldbus systems. The drive systems can be connected with the CNC via an analog/encoder interface or directly via a digital drive interface (e.g. EtherCAT, PROFIBUS DP/MC, SERCOS or Lightbus). This offers maximum openness and independence in the choice of I/O and drive systems for the user.
The required axis and spindle functions, interpolation and feed functions, tool and help functions according to DIN 66025 with specific expansions are available for a variety of machining technologies (e.g. milling, drilling, handling, special machines).
Interpolation with 64 axes
Complex machining tasks often require path movements involving a large number of axes and spindles. TwinCAT CNC can operate with 64 axes/controlled spindles that can be distributed across up to 12 CNC channels. In a CNC channel, up to 32 axes can be interpolated simultaneously, enabling even the most difficult motion tasks to be solved.
HSC technology (high-speed cutting)
Advanced HSC cutting technology requires CNC control technology with optimized solutions for Motion Control in order to achieve optimum results in terms of processing time while at the same time offering maximum accuracy and workpiece surface quality.
The TwinCAT CNC HSC pack offers the following options:
velocity and acceleration control across blocks for optimum utilization of axis dynamics and therefore higher achievable path velocities
high surface quality through smoothed dynamics and associated reduction of vibrational excitation of the machine
effective control of specified contour tolerances
Real-time transformations
Complex machine kinematics with difficult machining tasks require real-time transformations within the CNC for simple and flexible operation and programming. They are used, for example, for defining different coordinate systems within the machining process or for generating automatic compensating movements of rotary axes. A classic application is 5-axis machining.
As an option, TwinCAT CNC provides special CNC functions for this:
RTCP function (rotation tool center point)
TLC function (tool length compensation)
kinematics selection from the kinematics library
definition of different coordinate systems
tool alignment in the chosen coordinate system
linking/transition of coordinate systems