TX1250 | TwinCAT NC PTP – Point-to-point axis positioning

Position control with the PC

TwinCAT NC PTP includes axis positioning software (set value generation, position control), an integrated software PLC with NC interface, operating program for commissioning and an I/O connection to the axes through various fieldbuses. TwinCAT NC PTP replaces conventional positioning modules and NC controllers.

 

NC PTP software on the PC

The controllers that are simulated by the PC cyclically exchange data with drives and measuring systems via the fieldbus.

The capacity of a PC allows axes to be moved in parallel with the PLC functionality. PC power means that some tens of axes can easily be positioned simultaneously.

 

System structure

Axes are structured into channels for PTP movement and for interpolated movements.

 

Axis structure

TwinCAT NC PTP uses variables to operate axes. Each axis has variables for encoder, drive and controller. The axis can be linked to I/O interfaces, and parameters can be set.

 

Axis functions

Axis functions such as

• start (various modes)
• stop
• new target position and velocity
• constant drive output
• set/call actual position

 

Axis types

• servo axes
• high/low speed axes
• stepper motor axes
• “low-cost” stepper motor axes
• encoder axes
• simulation axes
• DC drives

 

Position measurement systems

The position controller acquires the actual position through:

• incremental encoders
• absolute encoders
• digital interfaces to the drives

 

Drive interfaces

• analog
• EtherCAT
• SERCOS
• SSI
• Lightbus
• PROFIBUS DP/MC
• pulse train

 

Interfaces

• interfacing to all popular fieldbuses, e.g. EtherCAT, Lightbus, SERCOS, PROFIBUS DP/MC, synchron CAN
• Axis functions can be embedded into the IEC 61131-3 PLC system by means of function block libraries; the function blocks comply with the PLCopen standard.
• data interface to Windows NT/2000/XP/Vista/CE or Windows 7 programs by means of open standards (OPC, Beckhoff ADS)

Positioning is executed with a powerful, modern positioning algorithm in which profiles are generated with jerk limitation and with pre-control of speed and acceleration to minimise the following error.

Positioning facilities:

• Controller structures can be adjusted.
• P controller
• PID controller
• PID with speed pre-control
• PID with speed and acceleration pre-control
• override functions

 

Commissioning/servicing

The online menu allows important axis parameters such as

• target position,
• set speed,
• acceleration, jerk,
• reference speed,
• controller Kv factor,

to be set, and general axis functions to be called such as

• start,
• stop/emergency stop,
• new target position with new speed.

 

Special functions

• linear coupling (electrical gears)
• distance compensation
• online master/slave and slave/master conversion
• “flying saw” (diagonal saw)
• camming (support through TwinCAT Cam Design Tool)
• FIFO axes
• change over encoders/controllers
• external axis set value generator
• multi-master coupling

Technical data	TX1250 | TwinCAT NC PTP
PC hardware	standard PC/IPC hardware, no extras
Operating systems	version-dependent: Windows 7/10, Windows CE
Real-time	Beckhoff real-time kernel (only 32-bit operating systems, only one core is used)
Runtime system	NC point-to-point (NC PTP) including TwinCAT PLC
Number of axes	up to 255 axes
Axis types	electrical and hydraulic servo drives, frequency converter drives, stepper motor drives, DC drives, switched drives
Cycle time	50 µs upwards selectable (typically 1 ms)
Axis functions	standard axis functions: start/stop/reset/reference, speed override, destination override; special functions: master-slave cascading, electronic gearing, online distance compensation
Programming	performed using IEC 61131-3 function blocks in the TwinCAT PLC, convenient methods for axis commissioning
Debugging	online monitoring of all axis state variables such as actual/set value, enable, controller values, online axis tuning, forcing axis variables
Configuration	all axis parameters such as the measuring system, drive parameters and position controller can be conveniently configured
Remanence	remanent data, UPS-supported storage on hard disk
I/O system	free choice of fieldbus: EtherCAT, PROFIBUS DP/MC, CANopen, DeviceNet, Interbus, SERCOS, Lightbus, Ethernet
Connectivity	variable access via OPC, Beckhoff ADS OCX/DLL

Ordering information
TX1250	license for using the PTP positioning software with integrated IEC 61131-3 TwinCAT PLC, contains programming software and runtime system

Options
TS5050	IEC 61131-3 software library for TwinCAT, implemented camshaft functionality (table coupling)
TS5060	IEC 61131-3 software library for TwinCAT, permits specified FIFO set value generation
TS5055	IEC 61131-3 software library for TwinCAT, implements a “flying saw”
TS1510	graphical development tool for programming cams
TS1500	graphics-oriented editor for designing the characteristic curve of a hydraulic valve