Revision September 2012 12-1Chapter 12 Absolute SystemIntroductionUsually, an absolute system is used in industrial applications which require knowing theactual position and continuing the operation at any time even if the power is turned off. Toprevent errors in operation, an absolute system is necessary.Delta’s absolute system includes at least an ASDA-A2 series servo drive, an ECMA series servomotor with an absolute encoder and a backup battery box for an absolute encoder.An ECMA series servo motor with an absolute encoder has an encoder which is able to rotateand tell the servo motor the actual position when the power is turned on. An absolute encoderin an ECMA series servo motor will constantly record the actual positions by its built-incoordinate system at any time. So the real position of the servo motor will be measured andrecorded even if the motor shaft rotates after the power is turned off.An ECMA series servo motor with an absolute encoder is essential and must be connectedwith an ASDA-A2 series servo drive for a Delta’s absolute system. When an ECMA series servomotor with an incremental encoder is connected to an ASDA-A2 series servo drive, if the usersenable the servo parameters for absolute system, a fault code, AL069 will be shown on thedrive’s LCD display to alert that an error occurs. When AL069 is displayed, please examine ifthe connected servo motor is a servo motor with an absolute encoder. The model name of aservo motor with an absolute encoder is shown as belowECMA- A(The boxes () in the servo motor model names are for rated voltage and rated speed, pleaserefer to the ordering information of the actual purchased products.)An absolute system needs one or more backup battery boxes for operation. When the backupbattery boxes are connected, the servo motors will continue working with the batteries after apower interruption. One servo drive uses one single battery box. Two servo drives can share adual battery box. We recommend the users to choose Delta’s backup battery boxes andDelta’s encoder connection cables for Delta’s absolute systems for wiring and connection.Please perform the installation in order as specified in the quick start and user manual whenconnecting to an absolute system. Regarding the descriptions and specifications of batteryboxes and corresponding accessories, please refer to the contents in the following sections.A: Servo Motor with Absolute Encoder
