High-performance servo systems can be configured in minutes

Festo's CMMP-AS premium servo motor controllers are available with a choice of four different power ratings to simplify application matching. Two models, with power output ratings of 0.5kVA and 1.0kVA, are designed for operation from single-phase 115-230V AC supplies; two larger models, rated at 3.0kVA and 6.0kVA, are intended for operation from three-phase 230-480V AC supplies. The single-phase models feature active power factor correction (PFC) and all four models use high, tightly-regulated bus voltages to maximise efficiency and ensure consistent operational performance in the event of varying supply voltages, anywhere in the world. The single-phase models use a 360V DC bus voltage and the three-phase models use a 600V DC bus voltage, thereby maximising available motor current and torque.

The 0.5kVA and 1.0kVA controllers can deliver peak currents of 5A and 10A, respectively, for up to 5s, while the 3.0kVA and 6.0kVA models can deliver up to 20A and 40A, respectively, for up to 3s. These very high peak current capabilities make CMMP-AS servo controllers particularly suitable for highly dynamic positioning applications involving extremely high accelerations and decelerations. The controllers are also compatible with linear motors.

Fieldbus communications

All CMMP-AS servo controllers feature a built-in CANopen fieldbus interface as standard, giving users access to a wide variety of low-cost I/O control options. Festo also offers a choice of ProfiBus, DeviceNet and Sercos interface options - the controller's front panel has two slots for field-replaceable plug-in fieldbus modules - together with an optional Ethernet port for remote, internet-based diagnostics. RS232 and RS485 serial interfaces are also provided as standard.

Festo's CMMP-AS servo controllers are claimed to be exceptionally easy to commission: all set-up parameters - including complete move profiles defining velocity, acceleration and deceleration - are developed off-line on a PC using the company's intuitive Windows-based FCT software, and then downloaded to the controller. As many as 256 move profiles can be stored on the controller and linked together, so that entire motion control sequences can be executed autonomously, entirely independently of the host PLC. Additional move profiles can be specified via fieldbus whenever required using the standard fieldbus FHPP handling and positioning profile.

The CMMP-AS controller accepts industry-standard +/-10V analogue speed-direction inputs and features extensive I/O facilities, including a dedicated input for high-speed position capture signals, with a response time of less than 1 microsecond. Two encoder inputs and an encoder output are provided as standard to support master-slave operation for flying saw type applications and electronic cam operation for applications such as carton folding. The FCT software includes a fully-integrated e-cam editor that simplifies the creation of jerk profiles. Operational performance is further enhanced by an innovative tolerance compensation feature; various tolerances in the overall drive system, such as belt expansion or screw gain throughout the stroke of a move, can be preloaded into a lookup table and used for dynamic correction.

CMMP-AS controllers also feature an advanced all-electronic "safe torque off' function that meets the safety requirements of EN 954-1 safety category 3, IEC 61508 and EN ISO 13849-1. This function replaces the conventional electromechanical contact breakers with a fail-safe signalling system and specialised power semiconductors in a dual-redundant configuration. Its advantages include simpler, lower cost installation due to the absence of external contact breakers, and much faster recovery from an emergency-stop (unlike conventional controller/drive systems, the reservoir capacitors are instantly disconnected from the power output bus in the event of an emergency-stop, and consequently do not require recharging afterwards).

Synchronous servo motors

Concomitant with the launch of the CMMP-AS range of controllers, Festo is also introducing no less than ten new fully compatible high-performance synchronous servo motors, with a choice of five frame sizes and single or dual stacks, spanning a continuous output torque range of 0.26-25.5Nm. When used with the 6.0kVA controller, the largest servo motor - which is a dual-stack, 140 frame size unit - can deliver peak torques as high as 48Nm at speeds up to 1400rpm. All ten servo motors, which are known as the EMMS-AS models, feature built-in Heidenhain absolute single-turn shaft encoders as standard, and are optionally available with high-resolution multi-turn absolute inductive encoders.

The motor housing and power connectors of Festo's EMMS-AS servo motors have an IP65 rating and the shaft has an IP41 rating, with an IP54 rated shaft seal available as an option. The motors have an ambient operating temperature range of -20 to +40degC, or up to +130degC with derating. The mounting flanges and shaft dimensions of the EMMS-AS motors are fully compatible with those of Festo's current MTR-AC range of servo motors, enabling customers to upgrade their existing automation systems very easily. EMMS-AS servo motors are supplied complete with flange, coupling and coupling housing, and Festo offers a wide range of compatible motor cables and planetary gearboxes to help simplify installation even further.

Festo's entire range of CMMP-AS premium servo controllers, EMMS-AS servo motors and ancillary components - including all the gearboxes - are held in stock and are available for immediate delivery.

For more information, go to www.festo.com/Automation/Innovations2007/125_758.htm.