This section describes the software configuration process for the Yaskawa Sigma II/III Serial Absolute Encoders. These encoders include the 16-bit, 17-bit and 20-bit single turn resolution versions. The multi-turn counter is maintained with an external battery when the controller is powered down.
NOTE: Unlike other absolute encoders, the Sigma II/III does not have an internal battery or capacitor that can retain the multi-turn data. Therefore, if the external battery is disconnected while the controller's power is off or the cable from the controller to the encoder is disconnected at anytime, the multi-turn data will be lost and the absolute position of the motor and encoder has to be reestablished (see the Yaskawa Sigma II/III Encoder Support Procedures and Alarms section of this document).
The following instructions only document the Parameter Database values that must be set differently from the standard incremental encoder configuration process.
To begin, the general servo parameters must be defined.
| DataID | Parameter Name | Description |
|---|---|---|
|
10008 |
Servo board configuration code |
Set to "-1" to indicate a special configuration is being defined by DataID's 10020 to 10048. |
|
10026 |
Encoder hardware channel number |
Set the array element that corresponds to the motor to the differential encoder channel connected to the Yaskawa Sigma II/III encoder ("1", "2", "3" or "4"). |
|
10027 |
Encoder type |
Set the array element that corresponds to the motor to one of the following values: |
After these values are set, the parameters must be saved to flash and the controller must be restarted.
Next the basic encoder parameters must be defined.
|
DataID |
Parameter Name |
Description |
|---|---|---|
|
10203 |
Encoder counts for resolution calc |
Set the array element that corresponds to the encoder to one of the following values: |
|
10204 |
Encoder revs for resolution calc |
Set the array element that corresponds to the encoder to "1". |
|
10208 |
Run-time speed limit |
Set the motor speed limits to proper values for your application to signal an error if the motor spins too quickly. |
|
10209 |
Manual mode speed limit |
|
|
10210 |
Power sequence speed limit |
Define the amplifier and motor data as follows:
| DataID | Parameter Name | Description |
|---|---|---|
|
10651 |
# of pole-pairs per motor revolution |
Set the array element that corresponds to the motor according to the motor specification data sheet. Alternately, use the configuration wizard in the Guidance Development Suite to discover the proper values. |
|
10652 |
Commutation counts per electrical cycle |
|
|
10656 |
Current loop proportional gain, Kp |
Perform the current loop tuning per the standard procedures described in the First Time Mechanism Integration section. |
|
10657 |
Current loop damping gain, Kv |
Next, the motor commutation reference angle must be established. Since the Yaskawa motor with the Sigma II/III encoder ensures that there is a fixed relationship between the single turn encoder position and the motor commutation angle, this relationship only has to be determined once for a given motor type.
| DataID | Parameter Name | Description |
|---|---|---|
|
10700 |
Commutation reference setup config |
Set the array element that corresponds to the motor to "4" to indicate that a serial absolute encoder is being used. |
|
10775 |
Commutation offset |
Set the array element that corresponds to the motor to "-1" to indicate that the offset has not been determined. |
To have the system automatically determine the "Commutation offset" (DataID 10775) perform the Twang-reference operation via DataID 14052. At the conclusion of this operation, the value of the "Commutation offset" (DataID 10775) will be set. After these values are saved and stored to the controller's flash disk, the next time the controller is restarted, this offset will be used with the single turn motor position to establish the commutation reference angle.
The final step is to set the homing method and to define the offset between the absolute encoder's zero position and the zero position for the axis.
| DataID | Parameter Name | Description |
|---|---|---|
|
2803 |
Homing method |
Set the array element that corresponds to the motor to "-9" to indicate that the absolute position from the encoder is to be used for homing. |
|
16120 |
Calibration home offset |
Follow the standard procedures for setting the offset between the motor and axis zero position. |