In the eXtended Transport System (XTS),Beckhoff combines the advantages of linear and rotary drives and thus offers a compact solution for innovative machine concepts. At the heart of the solution is the replacement of conventional drive components: Whereas in most conventional linear drives, static magnetic rails are usually driven by electrically connected movers, the XTS works in exactly the opposite way. The three main components are the static linear motor, a parallel guide rail and the passive mover itself. This concept makes the system a linear drive that moves in a circle. The independent passive carriages (the movers), which require no data or power supply via a drag chain or sliding contact, can travel both straight and curved paths. This allows closed circuits to be formed, which implies a high efficiency gain. While linear systems usually cover a working path and a passive path, the movers in a circuit can reduce the empty paths and thus increase system efficiency.

The XTS motor forms a fully integrated unit consisting of power electronics and path detection, in which solenoid coils set a passive mover in motion in a controlled manner via a double air gap. The motor can enable the movers to move at precisely positioned speeds of up to 4 m/s - both in a straight line and in curves. To provide the right guidance, the motor modules are combined with the appropriate guide rails. Depending on the application, the carriages can be moved on the inside or outside of the radii.
The mover contains magnetic plates which, together with the motor module, generate the propulsion force. Thanks to clever geometry and opposing magnetic field exciters, hardly any drive forces act on the bearing, even in force-intensive applications. This protects the bearings and saves drive energy for the application.

The movers can accelerate, brake, position and synchronize themselves; they can assume absolute and relative positions to each other, can group and accumulate, and generate clamping forces in motion. In addition, they can negotiate bends just as quickly as straight lines, recover energy through regenerative braking and use the return as well as the outward paths for transportation purposes. All of this is precisely position-controlled, with no vibrations, no play, no material fatigue, virtually no wear and no cost-intensive maintenance. While
While conventional transport systems use numerous bearings, chain drives, conveyor belts, trailing cables or sliding contacts that require regular maintenance, 'XTS' works with a minimum of mechanically moving parts.
This makes it much easier, for example, to adapt the format when changing products: if the transport route has to be reconfigured, only the finished motor and rail components need to be reconfigured. If the route remains the same and the parameters of the product change, this can be adapted by simply changing the software parameters.

Flexible and reliable

The 'ix Industrial' Ethernet connector from Harting is at least 50 % smaller than RJ45 interfaces and therefore makes a valuable contribution to miniaturization, not only in the 'XTS' (eXtended Transport System) from Beckhoff.

© Harting

Operational safety is also positively influenced. Conventional conveyor systems are driven by belts, chains or belts. Long stretches of transport media are often mechanically connected to each other. This means that the drive must apply the total force for all the conveyor systems, which is the sum of the individual forces required for all components. If a malfunction, collision or similar occurs, the total force of the entire system acts on one point. These forces can quickly lead to serious destruction. With 'XTS', on the other hand, only the individual force of a mover acts, which is significantly lower.

24 instead of twelve ports

© Harting

As the movers move along the track and follow their planned movement pattern - such as unlocking, clamping, releasing, braking, etc. - a computer must always calculate the circuit and current supply of the relevant motor modules. A total of three computer cards can be combined for this purpose. Until now, each of these had four RJ45 sockets as ports. As a rule, a motor module length of 1.5 m is controlled per port. However, even if user requirements regarding the size and complexity of the transport tasks to be implemented are increasing, the compact dimensions of the individual components should be retained. A more space-saving alternative is therefore required.
The Ethernet connector 'ix In-dustrial' from Harting is therefore installed in the current XTS generation. This interface is at least 50 % smaller in the device than RJ45 interfaces, while being more robust and equipped with a stable metallic locking mechanism. The 5000 possible mating cycles are not relevant in the XTS project, but illustrate the robust design of the interface. Power transmission via PoE/PoE+ is just as secure as the reliable hold on the PCB thanks to several THR shield contacts. The ix interface is standardized according to IEC 61076-3-124 and is therefore an open standard and not a specialized isolated solution.
In addition to saving space per port and robustness, reliable shielding and high data transfer rates were also required.

The umbrella concept

Jonas Diekmann is a technical editor at the Harting Technology Group in Espelkamp.

© Harting

With 1/10 Gbit/s Ethernet interfaces, it is a challenge to effectively minimize crosstalk between the individual data pairs in the small design with very closely spaced contacts. Harting ensures this by means of shielding concealed between the two rows of contacts, which effectively prevents crosstalk. In addition, the 'ix Industrial' has ten contacts, eight of which transmit data and two of which are connected to the ground potential on the PCB. They serve as additional shielding. The shielding plate and the earthed contacts result in an arrangement of the signal-carrying contacts similar to that of an x-coded M12 circular connector. Each wire pair is well shielded from its neighbors in its own cable or connector quadrant. This measure provides effective protection against crosstalk and enables interference-free data transmission.

For the XTS system, two 100 Mbit Ethercat connections are implemented for each ix-Industrial plug connection. This means that a total of eight instead of four ports can be installed on the same PCB and two instead of one Ethercat channel can be used per port. Calculated over three PCBs, the bottom line is 24 ports with 48 Ethercat strands instead of the previous twelve! This means that distances of up to 100 m can be realized.