# System

Identity, saving, resetting, errors, the watchdog, the heartbeat and the settings.

### Send_CAN_ID

<div class="cmd-facts" markdown><span class="fact">ID 11</span><span class="fact">host → driver</span><span class="fact">1 bytes</span><span class="fact">Python: `Send_CAN_ID()`</span></div>

Gives the driver a new node ID, 0 to 13 (the firmware accepts up to 15, but the bootloader reserves 14 and 15: a driver on one of those cannot be updated over CAN). Saving the configuration (Send_Save_config) also writes the ID into the bootloader's board ID. The driver answers to the new ID at once; the ID is kept over a power cycle only after Send_Save_config.

**1 bytes**

| Byte | Bit | Field | Type | Meaning |
|---|---|---|---|---|
| 0 |  | ID | unsigned 8-bit | 0 to 13; 14 and 15 are accepted but reserved by the bootloader |

The driver does not answer this command.

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### Send_ESTOP

<div class="cmd-facts" markdown><span class="fact">ID 0</span><span class="fact">host → driver</span><span class="fact">0 bytes</span><span class="fact">Python: `Send_ESTOP()`</span></div>

Stops the motor and raises the E-stop error, which stays until Send_Clear_Error.

The driver does not answer this command.

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### Send_Idle

<div class="cmd-facts" markdown><span class="fact">ID 12</span><span class="fact">host → driver</span><span class="fact">0 bytes</span><span class="fact">Python: `Send_Idle()`</span></div>

Puts the driver in idle mode (the motor coasts or brakes, see Send_Settings).

The driver does not answer this command.

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### Send_Save_config

<div class="cmd-facts" markdown><span class="fact">ID 13</span><span class="fact">host → driver</span><span class="fact">0 bytes</span><span class="fact">Python: `Send_Save_config()`</span></div>

Writes the current configuration (gains, limits, calibration, CAN ID, heartbeat, watchdog, gripper flag) to the EEPROM, and the CAN ID into the bootloader's board ID. The idle behaviour of Send_Settings and the current loop bandwidth are not kept. It also writes the serial number held in RAM, which is 1 after a power-up unless `#SERNUM` set it, over the stored one.

The driver does not answer this command.

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### Send_Reset

<div class="cmd-facts" markdown><span class="fact">ID 14</span><span class="fact">host → driver</span><span class="fact">0 bytes</span><span class="fact">Python: `Send_Reset()`</span></div>

Resets the driver. From firmware 105 the reset lands in the bootloader, which waits 2 s for a flashing host and then starts the firmware again; this is how a firmware update begins.

The driver does not answer this command.

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### Send_Clear_Error

<div class="cmd-facts" markdown><span class="fact">ID 1</span><span class="fact">host → driver</span><span class="fact">0 bytes</span><span class="fact">Python: `Send_Clear_Error()`</span></div>

Clears the error flags and goes to idle. An error whose cause is still present comes straight back. A calibration error is cleared only by calibrating. A gripper E-stop comes back until the E-stop bit of Send_gripper_data_pack is 0 again.

The driver does not answer this command.

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### Send_Watchdog

<div class="cmd-facts" markdown><span class="fact">ID 15</span><span class="fact">host → driver</span><span class="fact">5 bytes</span><span class="fact">Python: `Send_Watchdog()`</span></div>

Sets the watchdog: when the time runs out the driver reports a watchdog error and stops. Every valid motion frame (Send_data_pack_1, Send_data_pack_PD, Send_data_pack_HALL, Send_gripper_data_pack) and every status request the driver answers resets it; the setting frames (gains, limits, Idle, Clear, Save, Settings and Send_Watchdog itself) do not. 0 turns it off (the default). The action byte is stored but not acted on by this firmware: the driver always stops into its idle behaviour. Send_Save_config keeps the watchdog, and a kept watchdog runs from power-up: a host that sends no motion frame or status request within the time finds the driver in watchdog error, and clears it with Send_Clear_Error.

**5 bytes**

| Byte | Bit | Field | Type | Meaning |
|---|---|---|---|---|
| 0-3 |  | Time | unsigned 32-bit | ms; 0 = off |
| 4 |  | Action | unsigned 8-bit | 0 idle, 1 hold, 2 brake (stored only) |

The driver does not answer this command.

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### Send_Heartbeat_Setup

<div class="cmd-facts" markdown><span class="fact">ID 30</span><span class="fact">host → driver</span><span class="fact">4 bytes</span><span class="fact">Python: `Send_Heartbeat_Setup()`</span></div>

Sets the heartbeat interval in ms; 0 turns the heartbeat off (the default). Kept by Send_Save_config.

**4 bytes**

| Byte | Bit | Field | Type | Meaning |
|---|---|---|---|---|
| 0-3 |  | Interval | unsigned 32-bit | ms; 0 = off |

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### Send_Settings

<div class="cmd-facts" markdown><span class="fact">ID 35</span><span class="fact">host → driver</span><span class="fact">0 bytes</span></div>

Sets boolean settings that have no command of their own: a mask byte says which settings the frame touches, a value byte gives their new values; settings outside the mask are left alone. Bit 0 is the idle behaviour: 1 brake (phases shorted), 0 coast. The setting is not kept by Send_Save_config: at power-up the driver brakes. Added in firmware 107. The Python library has no call for it yet.

**2 bytes**

| Byte | Bit | Field | Type | Meaning |
|---|---|---|---|---|
| 0 |  | Mask | unsigned 8-bit | bit 0 = write the idle behaviour |
| 1 |  | Value | unsigned 8-bit | bit 0: 1 brake, 0 coast |

The driver does not answer this command.

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### Send_Cyclic_command

<div class="cmd-facts" markdown><span class="fact">ID 29</span><span class="fact">host → driver</span><span class="fact">not implemented</span></div>

Reserved. The firmware has no handler for this ID and the Python library's call does nothing.

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