Interface offers co-ordinated multi-axis control

Edited by the Engineeringtalk editorial team Feb 7, 2005

SynqNet is an all-digital motion control interface designed to replace the noise-prone +/-10V analogue interface for controllers and servo drives.

SynqNet is an all-digital motion control interface designed to replace the noise-prone +/-10V analogue interface for controllers and servo drives.

The protocol was developed by Motion Engineering and introduced at the Semicon West trade show in July 2001.

Since the company's acquisition by Danaher Motion in May 2004, SynqNet has become an increasingly accessible interface in Europe.

SynqNet was designed by close co-operation with equipment manufacturers to meet the requirements of wafer handling, automated test equipment (ATE) and medical imaging systems.

These applications share common goals: first, they all require tightly co-ordinated multi-axis control.

Secondly they require the accurate positioning and a smooth response traditionally only available using the analogue torque interface.

Finally, all applications require fault tolerance and safety mechanisms to be built into the interface.

The physical layer of SynqNet is based on IEEE802.3 standards, the same physical layer of Ethernet.

The datalink and application layers are specifically designed for motion control applications.

A key advantage is SynqNet's reduced size Ethernet frame - 24byte instead of 74 - which enables faster and more predictable performance.

The full duplex system operates over two pairs of wires, one pair for "receive" data signals and the other pair for "transmit" data signals.

It can be configured in a string or a fault tolerant ring topology.

Although the SynqNet interface is based on IEEE802.3, the same physical layer as Ethernet, it should not be confused with industrial Ethernet and the various manifestations that are available.

Networks such as EtherCAT, Powerlink and Profibus IRT exist to replace traditional fieldbus networks and bring new functionality to automation systems.

SynqNet on the other hand supports up to 32 axes at servo update rates of up to 48kHz, making it suitable for machines requiring high levels of co-ordination and synchronisation between axes.

The nodes can be 100m apart.

SynqNet networks communicate with drives in a synchronous manner that all but eliminates the negative effects of jitter.

It limits skew to 20ns using special algorithms that measure the system skew and compensate for it in hardware.

Jitter and skew are guaranteed for any number of nodes or network traffic conditions.

SynqNet achieves high integrity data communications by using transformer isolation between every node, which eliminates ground loops and common-mode electrical noise that are the root cause of many intermittent and systematic motion performance problems.

The interface is built on openly available industry standard FPGAs (field programmable gate arrays), making it simple and cost effective for OEMs and drive vendors to embed SynqNet technology.

No ASICs or Ethernet switches are required to implement a SynqNet design.

SynqNet slave-device technology is openly available to qualified OEM machine builders and product developers.

SynqNet master-device technology is available under licence terms to OEM machine builders and product developers.

SynqNet is being rapidly adopted for high performance motion control applications in the semiconductor, SMT, medical, packaging, robotics and flat panel manufacturing industries.

Nine leading servo suppliers (Yaskawa Electric, Panasonic, AMC, Danaher Motion, Glentek, Trust Automation, Tamagawa Seiki, Sanyo Denki, and Soonhan Engineering) now offer over 50 different products directly to OEM customers.

As of January 2005, 83,000 axes have been shipped, more than 10,000 of which are in use in Europe.