This section describes the software configuration process for the serial encoders defined in the following list. Most of these encoder are absolute, i.e. they return valid multi-turn data even after the controller is powered down. All of these encoders have very similar, but not necessary identical, interfaces. Any differences between the interfaces are specifically called out in the following paragraphs.
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.
| Data ID | 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. |
|
10009 |
Motor map per robot |
|
|
10010 |
Amplifier type from hardware |
|
|
10011 |
Cross couple axis map per robot |
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 encoder ("1", "2", "3", etc.). |
|
10027 |
Encoder type |
Set the array element that corresponds to the motor to "40" to select the Panasonic A4 17-bit or Bosch absolute encoder, "41" to select the Panasonic 10000 serial incremental encoder, "45" to select the Tamagawa SA35-17/33Bit-LPS, or to "46" for the Tamagawa 17-bit serial incremental encoder. |
|
10028 |
Amplifier hardware channel number |
|
|
10029 |
Amplifier type |
|
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.
| Data ID | Parameter Name | Description |
|---|---|---|
|
10203 |
Encoder counts for resolution calc |
Set the array element that corresponds to the encoder to "131072" or "10000". This is 17-bits or 10000 counts of resolution, respectively. |
|
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:
| Data ID | Parameter Name | Description |
|---|---|---|
|
10612 |
RMS rated motor torque, tcnt |
|
|
10650 |
Commutation sign |
Set the array element that corresponds to the motor to "-1" for the recommended motor wiring. |
|
10651 |
# of pole-pairs per motor revolution |
Set the array element that corresponds to the motor to "4". |
|
10652 |
Commutation counts per electrical cycle |
Set the array element that corresponds to the motor to "32768" or "2500". This is for the 17-bit or 10000 count encoders, respectively. |
|
10656 |
Current loop proportional gain, Kp |
Set the array element that corresponds to the motor to "0.02". Since these vendors offer a number of different motors this value should be verified using the standard current loop tuning procedure. |
|
10657 |
Current loop damping gain, Kv |
Set the array element that corresponds to the motor to "0.12". Since these vendors offer a number of different motors this value should be verified using the standard current loop tuning procedure. |
Next, the motor commutation reference angle must be established. Since the motor 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.
| Data ID | 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 or serial incremental 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 or, for 10000 count encoders, this value should be set to "1040". |
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.
| Data ID | 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. |