SPA2-2 system description

The SPA2-2 is a digital servo power amplifier solution designed specifically for use with the Renishaw UCC BI brushless motor interface controller. It is capable of controlling up to seven axes of movement but is customer configurable to the requirements of the installation.

Basic configurations

• SPA2-2 3-axis: This is the basic 3-axis configuration suitable for conventional CMMs fitted with brushed dc motors and brushless ac motors. It can accommodate tacho, tacholess and encoder velocity feedback systems. An additional card can be fitted to extend this unit to a 4-axis system.
• SPA2-2 6-axis: This configuration is suitable for installations requiring between 4 or 6 axis amplifiers. Like the 3-axis version it can accommodate tacho, tacholess and encoder velocity feedback systems. An additional axis card can be fitted to extend this unit to a 7-axis system.
• Two 3-axis SPA2-2 units can be combined in a single system permitting a servo power amplifier solution with an overall power rating of 1100 W.

Configurable motor voltage

• The SPA2-2 motor voltage can be configured by software to support a wide range of motor voltages within the range of 12 V and 60 V. The current limit can also be configured up to a maximum of 5 A continuous, 10 A peak.
• The voltage setting of each axis is independent and therefore it is possible to have each machine motor driven by a different voltage.

DC analogue tacho, tacholess or encoder compatibility

• Renishaw's UCC BI and SPA2-2 control solutions have the ability to support different types of velocity control loop based on the feedback to the controller.
• Three control loop feedback methods are integrated into the standard design of the system, these are analogue tacho based feedback system from the motor, obtaining the feedback from the scales of the CMM or from a motor mounted rotary encoder system.