eXtreme Fast Control in the drive

The EtherCAT-based AX8000 multi-axis servo system combines powerful FPGA technology with Arm^® multi-core processors. The new multi-channel current control technology makes extremely short sampling and reaction times possible. The entirely hardware-implemented current controller combines the advantages of analog and digital control technology: Setpoint deviations of the current can be reacted to within 1 µs; the shortest current controller cycle time is 62.5 µs at a switching frequency of 8 kHz. The processing of the EtherCAT process data (actual and setpoint values) can take place without a processor almost without delay in the hardware, so that the minimum EtherCAT cycle time is only 62.5 µs.

Features of the AX8000 XFC servo system:

• EtherCAT cycle times ≤ 100 µs
• distributed clocks support
• extremely fast digital inputs
• oversampling technology integration

Distributed clocks are used to precisely synchronize several drive axes, e.g. in machine tools. Latching of positions is possible via fast digital inputs with timestamp. Due to support for oversampling technology, the process data can even be sampled several times within a communication cycle, if required, and transmitted to the controller via EtherCAT. The values are provided in higher resolution than the EtherCAT cycle time for scope recordings. The oversampling method is used in precision processing machines as well as in machines and plants where the evaluation of high-resolution measured values is technologically necessary.

One Cable Technology (OCT)

In 2011, Beckhoff introduced the One Cable Technology for servomotors. Since then OCT has revolutionized the servo market, because only one connection cable is required for motor current and encoder feedback. The AX8000 multi-axis servo system supports OCT, the One Cable Technology for power and feedback. In combination with the servomotors from the AM8000 (standard), AM8300 (water cooling), AM8500 (increased inertia), AM8700 (anodized surface) and AM8800 (stainless steel) series, the cabling is reduced to the obligatory motor cable, through which the feedback signals are also transmitted. As with the sensorless controller, the user saves having to use an additional feedback cable. All the information required for control purposes is transferred reliably and fail-safe via a digital interface.

Drive-integrated safety functions

The AX8000 with TwinSAFE supports the typical drive-integrated safety functions and meets the requirements of EN ISO 13849-1:2015 (Cat. 4, PL e), EN 61508:2010 (SIL 3) and EN 62061:2005 + A1:2013/A2:2015 (SIL CL3).

• stop functions (STO, SOS, SS1, SS2)
• speed functions (SLS, SSM, SSR, SMS) at up to 8 speeds
• position functions (SLP, SCA, SLI) with referencing cams
• acceleration functions (SAR, SMA)
• direction of rotation functions (SDIp, SDIn)
• brake functions (SBC, SBT)