Currently, only absolute motor encoders of Yaskawa SGDM Sigma Series II Servopacks are supported by the MPI. Custom firmware is needed in order to use these absolute encoders. Contact MEI for more information.

The encoders are automatically interrogated at power-up or after a controller reset. Axis Origin and Command Positions are set to correctly reflect the absolute position of the motor with no position error initially. The absolute position is the position within a single revolution.

The encoder interrogation is controlled by a SEN signal (to the drive) which must be connected to a configured XMP Transceiver or User Out signal. There are no restrictions as to which XMP signal is used except that current drive limitations may limit the number of drives connected to the same XMP signal.

The MEIMotorEncoder{} structure has been added to the MEIMotorConfig{} object:

typedef struct MEIMotorEncoder {
    MEIXmpEncoderType     type;
    long                  countsPerRev;
} MEIMotorEncoder;

typedef struct MEIMotorConfig {
    MEIMotorEncoder    Encoder[MEIXmpMotorEncoders];
    MEIXmpIO           StatusOutput[MEIXmpMotorStatusOutputs];

    MEIMotorTransceiver     Transceiver[MEIXmpMotorTransceivers];
    long                    UserOutInvert;     /* Opto Polarity */
    MEIMotorStepper         Stepper;
    long                    EncoderTermination;

    /* Commutation is read-only from field Theta to end*/
    MEIXmpCommutationBlock     Commutation;

    MEIXmpLimitData     Limit[MEIXmpLimitLAST];

    MEIMotorFilterInput     FilterInput[MEIXmpMotorFilterInputs];
} MEIMotorConfig;