This is the description of the TCP/IP protocol for the Stepper Brick. General information and technical specifications for the Stepper Brick are summarized in its hardware description.
A general description of the TCP/IP protocol structure can be found here.
Function ID: | 1 |
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Request: |
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Response: | no response |
Sets the maximum velocity of the stepper motor in steps per second. This function does not start the motor, it merely sets the maximum velocity the stepper motor is accelerated to. To get the motor running use either set_target_position, set_steps, drive_forward or drive_backward.
Function ID: | 2 |
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Request: | empty payload |
Response: |
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Returns the velocity as set by set_max_velocity.
Function ID: | 3 |
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Request: | empty payload |
Response: |
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Returns the current velocity of the stepper motor in steps per second.
Function ID: | 4 |
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Request: |
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Response: | no response |
Sets the acceleration and deacceleration of the stepper motor. The values are given in steps/s². An acceleration of 1000 means, that every second the velocity is increased by 1000 steps/s.
For example: If the current velocity is 0 and you want to accelerate to a velocity of 8000 steps/s in 10 seconds, you should set an acceleration of 800 steps/s².
An acceleration/deacceleration of 0 means instantaneous acceleration/deacceleration (not recommended)
The default value is 1000 for both
Function ID: | 5 |
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Request: | empty payload |
Response: |
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Returns the acceleration and deacceleration as set by set_speed_ramping.
Function ID: | 6 |
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Request: | empty payload |
Response: | no response |
Executes an active full brake.
Warning
This function is for emergency purposes, where an immediate brake is necessary. Depending on the current velocity and the strength of the motor, a full brake can be quite violent.
Call stop if you just want to stop the motor.
Function ID: | 11 |
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Request: |
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Response: | no response |
Sets the number of steps the stepper motor should run. Positive values will drive the motor forward and negative values backward. The velocity, acceleration and deacceleration as set by set_max_velocity and set_speed_ramping will be used.
Function ID: | 12 |
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Request: | empty payload |
Response: |
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Returns the last steps as set by set_steps.
Function ID: | 13 |
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Request: | empty payload |
Response: |
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Returns the remaining steps of the last call of set_steps. For example, if set_steps is called with 2000 and get_remaining_steps is called after the motor has run for 500 steps, it will return 1500.
Function ID: | 16 |
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Request: | empty payload |
Response: | no response |
Drives the stepper motor forward until drive_backward or stop is called. The velocity, acceleration and deacceleration as set by set_max_velocity and set_speed_ramping will be used.
Function ID: | 17 |
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Request: | empty payload |
Response: | no response |
Drives the stepper motor backward until drive_forward or stop is triggered. The velocity, acceleration and deacceleration as set by set_max_velocity and set_speed_ramping will be used.
Function ID: | 18 |
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Request: | empty payload |
Response: | no response |
Stops the stepper motor with the deacceleration as set by set_speed_ramping.
Function ID: | 22 |
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Request: |
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Response: | no response |
Sets the current in mA with which the motor will be driven. The minimum value is 100mA, the maximum value 2291mA and the default value is 800mA.
Warning
Do not set this value above the specifications of your stepper motor. Otherwise it may damage your motor.
Function ID: | 23 |
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Request: | empty payload |
Response: |
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Returns the current as set by set_motor_current.
Function ID: | 24 |
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Request: | empty payload |
Response: | no response |
Enables the driver chip. The driver parameters can be configured (maximum velocity, acceleration, etc) before it is enabled.
Function ID: | 25 |
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Request: | empty payload |
Response: | no response |
Disables the driver chip. The configurations are kept (maximum velocity, acceleration, etc) but the motor is not driven until it is enabled again.
Function ID: | 26 |
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Request: | empty payload |
Response: |
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Returns true if the driver chip is enabled, false otherwise.
Function ID: | 7 |
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Request: |
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Response: | no response |
Sets the current steps of the internal step counter. This can be used to set the current position to 0 when some kind of starting position is reached (e.g. when a CNC machine reaches a corner).
Function ID: | 8 |
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Request: | empty payload |
Response: |
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Returns the current position of the stepper motor in steps. On startup the position is 0. The steps are counted with all possible driving functions (set_target_position, set_steps, drive_forward or drive_backward). It also is possible to reset the steps to 0 or set them to any other desired value with set_current_position.
Function ID: | 9 |
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Request: |
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Response: | no response |
Sets the target position of the stepper motor in steps. For example, if the current position of the motor is 500 and set_target_position is called with 1000, the stepper motor will drive 500 steps forward. It will use the velocity, acceleration and deacceleration as set by set_max_velocity and set_speed_ramping.
A call of set_target_position with the parameter x is equivalent to a call of set_steps with the parameter (x - get_current_position).
Function ID: | 10 |
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Request: | empty payload |
Response: |
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Returns the last target position as set by set_target_position.
Function ID: | 14 |
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Request: |
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Response: | no response |
Sets the step mode of the stepper motor. Possible values are:
A higher value will increase the resolution and decrease the torque of the stepper motor.
The default value is 8 (Eighth Step).
Function ID: | 15 |
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Request: | empty payload |
Response: |
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Returns the step mode as set by set_step_mode.
Function ID: | 19 |
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Request: | empty payload |
Response: |
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Returns the stack input voltage in mV. The stack input voltage is the voltage that is supplied via the stack, i.e. it is given by a Step-Down or Step-Up Power Supply.
Function ID: | 20 |
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Request: | empty payload |
Response: |
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Returns the external input voltage in mV. The external input voltage is given via the black power input connector on the Stepper Brick.
If there is an external input voltage and a stack input voltage, the motor will be driven by the external input voltage. If there is only a stack voltage present, the motor will be driven by this voltage.
Warning
This means, if you have a high stack voltage and a low external voltage, the motor will be driven with the low external voltage. If you then remove the external connection, it will immediately be driven by the high stack voltage
Function ID: | 21 |
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Request: | empty payload |
Response: |
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Returns the current consumption of the motor in mA.
Function ID: | 27 |
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Request: |
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Response: | no response |
Sets the decay mode of the stepper motor. The possible value range is between 0 and 65535. A value of 0 sets the fast decay mode, a value of 65535 sets the slow decay mode and a value in between sets the mixed decay mode.
Changing the decay mode is only possible if synchronous rectification is enabled (see set_sync_rect).
For a good explanation of the different decay modes see this blog post by Avayan.
A good decay mode is unfortunately different for every motor. The best way to work out a good decay mode for your stepper motor, if you can't measure the current with an oscilloscope, is to listen to the sound of the motor. If the value is too low, you often hear a high pitched sound and if it is too high you can often hear a humming sound.
Generally, fast decay mode (small value) will be noisier but also allow higher motor speeds.
The default value is 10000.
Note
There is unfortunately no formula to calculate a perfect decay mode for a given stepper motor. If you have problems with loud noises or the maximum motor speed is too slow, you should try to tinker with the decay value
Function ID: | 28 |
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Request: | empty payload |
Response: |
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Returns the decay mode as set by set_decay.
Function ID: | 33 |
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Request: |
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Response: | no response |
Turns synchronous rectification on or off (true or false).
With synchronous rectification on, the decay can be changed (see set_decay). Without synchronous rectification fast decay is used.
For an explanation of synchronous rectification see here.
Warning
If you want to use high speeds (> 10000 steps/s) for a large stepper motor with a large inductivity we strongly suggest that you disable synchronous rectification. Otherwise the Brick may not be able to cope with the load and overheat.
The default value is false.
Function ID: | 34 |
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Request: | empty payload |
Response: |
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Returns true if synchronous rectification is enabled, false otherwise.
Function ID: | 35 |
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Request: |
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Response: | no response |
Sets the time base of the velocity and the acceleration of the stepper brick (in seconds).
For example, if you want to make one step every 1.5 seconds, you can set the time base to 15 and the velocity to 10. Now the velocity is 10steps/15s = 1steps/1.5s.
The default value is 1.
Function ID: | 36 |
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Request: | empty payload |
Response: |
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Returns the time base as set by set_time_base.
Function ID: | 37 |
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Request: | empty payload |
Response: |
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Returns the following response values: The current velocity, the current position, the remaining steps, the stack voltage, the external voltage and the current consumption of the stepper motor.
There is also a callback for this function, see CALLBACK_ALL_DATA.
Function ID: | 238 |
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Request: | empty payload |
Response: | no response |
Enables the status LED.
The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.
The default state is enabled.
New in version 2.3.1 (Firmware).
Function ID: | 239 |
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Request: | empty payload |
Response: | no response |
Disables the status LED.
The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.
The default state is enabled.
New in version 2.3.1 (Firmware).
Function ID: | 240 |
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Request: | empty payload |
Response: |
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Returns true if the status LED is enabled, false otherwise.
New in version 2.3.1 (Firmware).
Function ID: | 241 |
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Request: |
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Response: |
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Returns the firmware and protocol version and the name of the Bricklet for a given port.
This functions sole purpose is to allow automatic flashing of v1.x.y Bricklet plugins.
Function ID: | 242 |
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Request: | empty payload |
Response: |
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Returns the temperature in °C/10 as measured inside the microcontroller. The value returned is not the ambient temperature!
The temperature is only proportional to the real temperature and it has an accuracy of +-15%. Practically it is only useful as an indicator for temperature changes.
Function ID: | 243 |
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Request: | empty payload |
Response: | no response |
Calling this function will reset the Brick. Calling this function on a Brick inside of a stack will reset the whole stack.
After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!
Function ID: | 255 |
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Request: | empty payload |
Response: |
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Returns the UID, the UID where the Brick is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be '0'-'8' (stack position).
The device identifier numbers can be found here.
Function ID: | 29 |
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Request: |
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Response: | no response |
Sets the minimum voltage in mV, below which the CALLBACK_UNDER_VOLTAGE callback is triggered. The minimum possible value that works with the Stepper Brick is 8V. You can use this function to detect the discharge of a battery that is used to drive the stepper motor. If you have a fixed power supply, you likely do not need this functionality.
The default value is 8V.
Function ID: | 30 |
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Request: | empty payload |
Response: |
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Returns the minimum voltage as set by set_minimum_voltage.
Function ID: | 38 |
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Request: |
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Response: | no response |
Sets the period in ms with which the CALLBACK_ALL_DATA callback is triggered periodically. A value of 0 turns the callback off.
Function ID: | 39 |
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Request: | empty payload |
Response: |
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Returns the period as set by set_all_data_period.
Function ID: | 31 |
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Response: |
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This callback is triggered when the input voltage drops below the value set by set_minimum_voltage. The response value is the current voltage given in mV.
Function ID: | 32 |
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Response: |
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This callback is triggered when a position set by set_steps or set_target_position is reached.
Note
Since we can't get any feedback from the stepper motor, this only works if the acceleration (see set_speed_ramping) is set smaller or equal to the maximum acceleration of the motor. Otherwise the motor will lag behind the control value and the callback will be triggered too early.
Function ID: | 40 |
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Response: |
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This callback is triggered periodically with the period that is set by set_all_data_period. The response values are: the current velocity, the current position, the remaining steps, the stack voltage, the external voltage and the current consumption of the stepper motor.
Function ID: | 41 |
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Response: |
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This callback is triggered whenever the Stepper Brick enters a new state. It returns the new state as well as the previous state.
Possible states are: