Still 3.0RC1 provisional

Bug fix: not all extrusion amounts were being cleared when preparing a move

6 files changed, 819 insertions, 7 deletions

diff --git a/HTTP requests.md b/HTTP requests.md
new file mode 100644
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--- /dev/null
+++ b/HTTP requests.md
@@ -0,0 +1,349 @@
+# List of supported HTTP requests
+
+RepRapFirmware provides an HTTP interface for dealing with client requests.
+These requests are tailored for Duet Web Control in the first place but they may be used by third-party applications, too.
+
+Every request except for `rr_connect` returns HTTP status code `401` if the client does not have a valid session.
+If no machine password is set, a user session is created whenever an arbitrary HTTP request is made.
+Besides, RepRapFirmware may run short on memory and may not be able to respond properly. In this case, HTTP status code `503` is returned.
+
+In the following requests datetime strings may be used. These datetime strings are very similar to ISO8601-encoded strings but they do not contain timezone details.
+An example for such a string is `2019-12-13T21:27:00`. Make sure to follow this format where applicable.
+
+## GET /rr_connect
+
+Attempt to create a new connection and log in using the (optional) password.
+
+Supported parameters:
+
+- `password` (optional): Machine password to log in with. If omitted, this defaults to `reprap`
+- `time` (optional): Current datetime that will be used to update RepRapFirmware's internal clock
+
+Returns
+
+```
+{
+    "err": code
+}
+```
+
+where `code` may be one of the following:
+
+- `0`: Password is valid and the client's IP address is added to the list of HTTP sessions
+- `1`: Password is invalid
+- `2`: No more user sessions available. This may occur when too many client devices are connected at the same time
+
+If the password is valid, extra fields are returned:
+
+```
+{
+    "err": 0,
+    "sessionTimeout": 8000,
+    "boardType": "duetwifi102"
+}
+```
+
+- `sessionTimeout` is the idle timeout in milliseconds before a client is removed again from the list of client sessions
+- `boardType` represents the board's type
+
+Officially supported board types are:
+
+| boardType | Board | Remarks |
+| --------- | ----- | ------- |
+| duet06 | Duet 0.6 | deprecated |
+| duet07 | Duet 0.7 | deprecated |
+| duet085 | Duet 0.8.5 | deprecated |
+| duetwifi10 | Duet WiFi v1.0 ||
+| duetwifi102 | Duet WiFi v1.02 ||
+| duetethernet10 | Duet Ethernet v1.0 ||
+| duetethernet102 | Duet Ethernet v1.02 ||
+| duetmaestro100 | Duet Maestro v1.0 ||
+| duet3mb6hc | Duet 3 v0.6 ||
+
+## GET /rr_disconnect
+
+Disconnect again from the RepRapFirmware controller.
+
+Returns
+
+```
+{
+    "err": code
+}
+```
+
+where `code` may be `0` if the session could be removed, else it is `1`.
+
+## GET /rr_status
+
+Retrieve a status response from RepRapFirmware in JSON format.
+
+Supported parameters:
+
+- `type`: Type of the status response
+
+The value of `type` can be one of:
+
+- 1: Standard status response
+- 2: Advanced status response. This also contains fields from the standard status response
+- 3: Print status response. This contains fields from the standard status response as well as information about the current (print) job
+
+See [JSON responses](JSON%20Responses.md) for further information.
+
+## Get /rr_config
+
+Retrieve the configuration response. This request provides a JSON object with values that are expected to change rarely. 
+
+See [JSON responses](JSON%20Responses.md) for further information.
+
+## GET /rr__gcode
+
+Execute arbitrary G/M/T-code(s).
+
+Supported parameters:
+
+- `gcode`: G/M/T-code to execute. This parameter must be present although it can be empty
+
+Returns
+
+```
+{
+    "buff": bufferSpace
+}
+```
+
+where `bufferSpace` indicates how much buffer space for new G/M/T-codes is still available.
+
+If a file is supposed to be streamed over the HTTP interface, call this repeatedly and transfer only as many bytes as allowed.
+
+## GET /rr_reply
+
+Retrieve the last G-code reply. The G-code reply is buffered per connected HTTP client and it is discarded when every HTTP client has fetched it or
+when the firmware is short on memory and the client has not requested it within reasonable time (1 second).
+
+The G-code reply is returned as `text/plain`.
+
+## GET /rr_upload
+
+Get the last file upload result.
+
+Returns
+
+```
+{
+    "err": code
+}
+```
+
+where `code` can be either `0` if the last upload successfully finished or `1` if an error occurred.
+
+## POST /rr_upload
+
+Upload a file.
+
+Supported URL parameters:
+
+- `name`: Path to the file to upload
+- `time` (optional): ISO8601-like represenation of the time the file was last modified
+- `crc32` (optional): CRC32 checksum of the file content as hex string *without* leading `0x`. Usage of this parameter is encouraged
+
+The raw HTTP body contains the file content. Binary file uploads are supported as well.
+Make sure to set `Content-Length` to the length of the HTTP body if your HTTP client does not already do that.
+
+Returns
+
+```
+{
+    "err": code
+}
+```
+
+where `code` can be either `0` if the last upload successfully finished or `1` if an error occurred (e.g. CRC mismatch).
+
+## GET /rr_download
+
+Download a file.
+
+Supported parameters:
+
+- `name`: Filename to download
+
+If the file could not be found, HTTP status code 404 is returned, else the file content is sent to the client.
+
+## GET /rr_delete
+
+Delete a file or directory.
+
+Supported parameters:
+
+- `name`: Filename to delete
+
+Returns
+
+```
+{
+    "err": {code}
+}
+```
+
+where code is either `0` on success or `1` on error.
+
+## GET /rr_filelist
+
+Retrieve a (partial) file list.
+
+Supported parameters:
+
+- `dir`: Directory to query
+- `first` (optional): First item index to return. Defaults to `0`
+
+Returns
+```
+{
+    "dir": dir,
+    "first": first,
+    "files": [
+        {
+            "type": itemType,
+            "name": itemName,
+            "size": itemSize,
+            "date": itemDate
+        },
+        ...
+    ],
+    "next": next,
+    "err": code
+}
+```
+
+where `dir` and `first` equal the query parameters. `err` can be one of:
+
+- `0`: List query successful
+- `1`: Drive is not mounted
+- `2`: Directory does not exist
+
+The `next` field may be omitted if the query was not successful and it is `0` if the query has finished. If there are more items to query, this value can be used for the `first` parameter of a successive `rr_filelist` request.
+
+Retrieved files are returned as part of the `files` array. Note that `date` may not be present if it is invalid. Every item has the following properties:
+
+- `itemType`: Type of the file item. This is `d` for directories and `f` for files
+- `itemName`: Name of the file or directory
+- `itemSize`: Size of the file. This is always `0` for directories
+- `itemDate`: Datetime of the last file modification
+
+## GET /rr_files
+
+Retrieve a list of files without any attributes.
+
+Supported parameters:
+
+- `dir`: Directory to query
+- `first` (optional): First item index to return. Defaults to `0`
+- `flagDirs` (optional): Set this to `1` to prefix directory items with `*`. Defaults to `0`
+
+Returns
+
+```
+{
+    "dir": dir,
+    "first": first,
+    "files": [
+        "file1",
+        "file2",
+        ...
+    ],
+    "next": next,
+    "err": err
+}
+```
+
+where `dir` and `first` equal the query parameters. `err` can be one of:
+
+- `0`: List query successful
+- `1`: Drive is not mounted
+- `2`: Directory does not exist
+
+The `next` field may be omitted if the query was not successful and it is `0` if the query has finished. If there are more items to query, this value can be used for the `first` parameter of a successive `rr_files` request.
+
+## GET /rr_move
+
+Move a file or directory.
+
+Supported parameters:
+
+- `old`: Current path to the file or directory
+- `new`: New path of the file or directory
+- `deleteexisting` (optional): Set this to `yes` to delete the new file if it already exists. Defaults to `no`
+
+Returns
+
+```
+{
+    "err": code
+}
+```
+
+where code is either `0` on success or `1` on error.
+
+## GET /rr_mkdir
+
+Create a new directory.
+
+Supported parameters:
+
+- `dir`: Path to the new directory
+
+Returns
+
+```
+{
+    "err": code
+|
+```
+
+where code is either `0` on success or `1` on error.
+
+## GET /rr_fileinfo
+
+Parse a G-code job file and return retrieved information. If no file is specified, information about the file being printed is returned.
+
+Supported parameters:
+
+- `name` (optional): Path to the file to parse
+
+Returns
+
+```
+{
+    "err": code,
+    "size": size,
+    "lastModified": lastModified,
+    "height": height,
+    "firstLayerHeight": firstLayerHeight,
+    "layerHeight": layerHeight,
+    "printTime": printTime,
+    "simulatedTime": simulatedTime,
+    "filament": filament,
+    "printDuration": printDuration,
+    "fileName": fileName,
+    "generatedBy": generatedBy
+}
+```
+
+where `code` is either `0` on success or `1` on error. If the file could not be parsed, all other fields are omitted.
+
+Other fields are:
+
+| Field | Unit | Description | Default value if invalid | Present if `name` is omitted |
+| ----- | ---- | ----------- | ------------------------ | --------------------------- |
+| size | bytes | Size of the file in bytes | not applicable | yes |
+| lastModified | datetime | Datetime of the last file modification | omitted | maybe |
+| height | mm | Final print height of the object | 0.00 | yes |
+| firstLayerHeight | mm | Height of the first layer | 0.00 | yes |
+| layerHeight | mm | Layer height | 0.00 | yes |
+| printTime | seconds | Estimated print time | omitted | maybe |
+| simulatedTime | seconds | Estimated print time according to the last simulation | omitted | maybe |
+| filament | array of mm | Total filament consumption per extruder | empty array | yes |
+| printDuration | seconds | Total print time so far | not applicable | no |
+| fileName | file path | Absolute path to the file being printed | not applicable | no |
+| generatedBy | text | Slicer or toolchain which generated this file | empty string | yes |
diff --git a/JSON responses.md b/JSON responses.md
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--- /dev/null
+++ b/JSON responses.md
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+# List of RepRapFirmware JSON Responses
+
+This document describes the four big JSON responses which are used to report status and configuration details.
+For a list of HTTP-related JSON responses, see [HTTP requests](HTTP%20requests.md).
+
+In these responses the following conditions apply:
+
+- Booleans represented as 0 (false) or 1 (true)
+- Indices pointing to another resource *might* not be valid. This is due to possible limitations of the CAN expansion board management
+- ADC readings are reported on a scale of 0 to 1000
+- Lengths are reported in mm
+- Speeds are reported in mm/s
+- Times are reported in seconds
+- Temperatures are reported in Celsius
+
+## Standard Status Response (Type 1)
+
+This status response contains various fields that are expected to change frequently. These values are also included in the type 2 and 3 status responses.
+
+```
+{
+	"status": "O",
+	"coords": {
+		"axesHomed": [0, 0, 0],
+		"wpl": 1,
+		"xyz": [0.000, 0.000, 0.000],
+		"machine": [0.000, 0.000, 0.000],
+		"extr": []
+	},
+	"speeds": {
+		"requested": 0.0,
+		"top": 0.0
+	},
+	"currentTool": -1,
+	"output": {
+		"beepDuration": 1234,
+		"beepFrequency": 4567,
+		"message": "Test message",
+		"msgBox": {
+			"msg": "my message",
+			"title": "optional title",
+			"mode": 0,
+			"seq": 5,
+			"timeout": 10.0,
+			"controls": 0
+		}
+	},
+	"params": {
+		"atxPower": -1,
+		"fanPercent": [-100],
+		"speedFactor": 100.0,
+		"extrFactors": [],
+		"babystep": 0.000,
+		"seq": 1
+	},
+	"sensors": {
+		"probeValue": 1000,
+		"probeSecondary": 1000,
+		"fanRPM": [-1]
+	},
+	"temps": {
+		"bed": {
+			"current": -273.1,
+			"active": -273.1,
+			"standby": -273.1,
+			"state": 0,
+			"heater": 0
+		},
+		"current": [-273.1],
+		"state": [0],
+		"tools": {
+			"active": [],
+			"standby": []
+		},
+		"extra": []
+	},
+	"time": 596.0,
+	"scanner": {
+		"status": "D",
+		"progress": 0.0
+	},
+	"spindles": [],
+	"laser": 0.0
+}
+```
+
+### Machine Status
+
+The `status` field provides a single character for the machine status. It may have one of the following values:
+
+| Status character | Status |
+| ---------------- | ------ |
+| C | Reading configuration file |
+| F | Flashing new firmware |
+| H | Halted (after emergency stop) |
+| O | Off (powered down, low input voltage) |
+| D | Pausing print (decelerating) |
+| R | Resuming print (after pause) |
+| S | Print paused (stopped) |
+| M | Simulating a (print) file |
+| P | Printing |
+| T | Changing tool |
+| B | Busy (executing macro, moving) |
+
+Values higher in the table also have a higher priority. So, for example, tool changes are not reported while a print is in progress.
+
+### Coordinates
+
+- `coords/wpl` (optional): Selected workplace (see G10 and G54 to G59.3). May not be present if the board does not support workplaces
+- `cords/xyz`: User coordinates of the axes (i.e. with tool offsets applied)
+- `coords/machine`: Mchine coordinate of the axes (i.e. without tool offsets applied)
+- `coords/extr` Total amount of filament extruded per extruder drive (with extrusion factors applied). See also `extrRaw` in response type 3
+
+### Output
+
+RepRapFirmware may request output via the client application. Only if this is the case, the `output` field is present.
+
+#### Beeps
+
+If no PanelDue is attached, beeps (see M300) are reported via the `beepDuration` and `beepFrequency` fields.
+These fields are not present if M300 was not used.
+
+#### Output message
+
+A user may want to output a generic message via M117. If this is the case, the message string is reported via the `message` field.
+
+#### Message boxes
+
+RepRapFirmware allows a user to use message boxes if required. These message boxes may be configured via M291/M292.
+The corresponding values can be found in the optional `msgBox` field. See the documentation of M291 for further details.
+
+- `msgBox/controls` is a bitmap of configured axis controls (X = 1, Y = 2, Z = 4 etc.)
+- `msgBox/seq` is incremented whenever M291 is used
+- `msgBox/timeout` is the time left for displaying this message box or 0.0 if it does not time out
+
+### Temperatures
+
+Slow heaters like `temps/bed`, `temps/chamber`, and `temps/cabinet` (second chamber) have the following properties:
+
+- `current`: Current heater temperature
+- `active`: Target temperature when turned on (in active state)
+- `standby`: Target temperature when in standby mode
+- `state`: State of the heater. See below
+- `heater`: Index of the assigned heater
+
+The fields `temps/bed`, `temps/chamber`, and `temps/cabinet` may not be present if no bed and/or chamber is configured.
+
+- `temps/current`: Array of heater temperatures
+- `temps/state`: Array of heater states
+- `temps/tools/active`: Array holding arrays of configured active heater temperatures. Tools may have multiple heaters assigned
+- `temps/tools/standby`: Array holding arrays of configured standby heater temperatures
+
+#### Heater states
+
+| Heater state | Meaning | Description |
+| ------------ | ------- | ----------- |
+| 0 | off | Heater is turned off |
+| 1 | standby | Heater is in standby mode |
+| 2 | active | Heater is active |
+| 3 | fault | Heater fault occurred |
+| 4 | tuning | Heater is being tuned |
+| 5 | offline | Remote heater from an expansion board is not available |
+
+#### Extra heaters
+
+Extra heaters represent custom sensor and can be found in `temps/tools/extra`. Every extra heater is reported in the following format:
+
+```
+{
+	"name": "MCU",
+	"temp": 34.7
+}
+```
+
+### Scanner
+
+RepRapFirmware may support an external interface for 3D scanners. This field is not be present if scanner support is not enabled in the firmware,
+hence this field may not be present either. There are two fields for this interface in the status response:
+
+- `status`: Status of the external 3D scanner. See below
+- `progress`: Progress of the current operation (0.0 to 100.0)
+
+Possible scanner states:
+
+| Status character | State |
+| ---------------- | ----- |
+| D | Disconnected |
+| I | Idle |
+| S | Scanning |
+| P | Post processing |
+| C | Calibrating |
+| U | Uploading |
+
+### Spindles
+
+The `spindles` field may be only present if the machine is in `CNC` mode or if the advanced status respone (type 2) is queried.
+
+It provides a list of configured spindles in the format
+
+```
+{
+	"current": 0.0,
+	"active": 0.0,
+	"tool": 0
+}
+```
+
+where `current` is the current RPM, `active` the target RPM, and `tool` the number of the assigned tool.
+
+### Other fields
+
+- `speeds/requested`: Requested feedrate of the current move
+- `speeds/top`: Top feedrate of the current move
+- `currentTool`: Selected tool number (not index) or -1 if none is selected
+- `params/atxPower`: ATX power state. This may be -1 if ATX power is not configured
+- `params/fanPercent`: Fan percent (0.0 to 100.0). If the fan is disabled, this may be negative (-1)
+- `params/speedFactor`: Speed factor override. 100% equals 100.0 and this is always greater than 0.0
+- `params/extrFactors`: Extrusion factor override values. Values of 100% equals 100.0 and they are always greater than 0.0
+- `params/babystep`: Z babystepping amount
+- `sensors/probeValue`: ADC reading of the Z probe
+- `sensors/probeSecondary` (optional): Seconday probe ADC reading if the probe is modulated. This field is not present if the probe is unmodulated
+- `sensors/fanRPM`: Array of fan RPMs, values may be negative if not configured
+- `time`: Time in seconds since the machine started. May be used to detect firmware resets
+- `laser` (optional): PWM value of the attached laser. This field is only present if the machine is in `Laser` mode
+
+## Advanced Status Response (Type 2)
+
+This status response type provides fields that may change but not as frequently as those in the standard status response.
+
+```
+{
+	"params": {
+		"fanNames": [""],
+	},
+	"temps": {
+		"names": [""}
+	},
+	...
+	"coldExtrudeTemp": 160.0,
+	"coldRetractTemp": 90.0,
+	"compensation": "None",
+	"controllableFans": 0,
+	"tempLimit": 290.0,
+	"endstops": 0,
+	"firmwareName": "RepRapFirmware for Duet 3 v0.6",
+	"firmwareVersion": "3.0beta12+1",
+	"geometry": "cartesian",
+	"axes": 3,
+	"totalAxes": 3,
+	"axisNames": "XYZ",
+	"volumes": 1,
+	"mountedVolumes": 0,
+	"mode": "FFF",
+	"name": "duet3",
+	"probe": {
+		"threshold": 500,
+		"height": 0.70,
+		"type": 0
+	},
+	"tools": [],
+	"mcutemp": {
+		"min": 24.0,
+		"cur": 37.4,
+		"max": 37.6
+	},
+	"vin": {
+		"min": 0.2,
+		"cur": 0.3,
+		"max": 0.3
+	},
+	"v12": {
+		"min": 0.2,
+		"cur": 0.2,
+		"max": 0.2
+	}
+}
+```
+
+### Geometry
+
+The current geometry is reported as part of the `geometry` field. The following geometries are supported:
+
+| Value | Geometry |
+| ----- | -------- |
+| cartesian | Cartesian |
+| coreXY | CoreXY |
+| coreXYU | CoreXYU |
+| coreXYUV | CoreXYUV |
+| coreXZ | CoreXZ |
+| markForged | markForged |
+| Hangprinter | Hangprinter |
+| delta | Linear delta |
+| Polar | Polar |
+| Rotary delta | Rotary delta |
+| Scara | Scara |
+
+If the geometry is unknown, `unknown` is reported.
+
+### Machine mode
+
+It is possible to choose between `FFF`, `CNC`, and `Laser` mode. As a consequence, the following values are reported as part of the `mode` field:
+
+| Value | Mode |
+| ----- | ---- |
+| FFF | 3D printing mode |
+| CNC | CNC mode |
+| Laser | Laser cutting/engraving mode |
+
+
+### Probe
+
+The `probe` field may not be present if no Z probe is configured. If it is, it provides the following fields:
+
+- `probe/threshold`: Threshold value for the Z probe to be triggered
+- `probe/height`: Z height of the Z probe when triggered
+- `probe/type`: Probe type. See below
+
+Possible probe types are:
+
+| Probe type | Name |
+| ---------- | ---- |
+| 0 | No probe |
+| 1 | Simple analog probe |
+| 2 | Dumb modulated probe |
+| 3 | Alternate analog probe |
+| 4 | E0 switch **deprecated** |
+| 5 | Digital probe |
+| 6 | E1 switch **deprecated** |
+| 7 | Z switch **deprecated** |
+| 8 | Unfiltered digital probe |
+| 9 | BLTouch |
+| 10 | Z motor stall detection |
+
+### Tool mapping
+
+In order to figure out the mapping between heaters and tools, the tool mapping is reported as part of the advanced status response.
+The tool mapping is reported as an array of items like
+
+```
+{
+	"number": 0,
+	"name": "",
+	"heaters": [],
+	"drives": [],
+	"axisMap": [[0],[1]],
+	"fans": 1,
+	"filament": "PLA",
+	"offsets": [0.00, 0.00, 0.00]
+}
+```
+
+where
+
+- `number`: Tool number (T*n*)
+- `name`: Optional tool name or `""` if none is configured
+- `heaters`: List of assigned heater indices
+- `drives`: List of assigned drives
+- `axisMap`: XY axis mapping. Mapped X axes are reported in the first item and mapped Y axes in the second one
+- `fans`: Bitmap of the mapped tool fans (controllable by `M106` without `P` parameter)
+- `filament` (optional): Name of the loaded filament
+- `offsets`: Tool offsets. The size of this array equals the number of visible axes
+
+### Other fields
+
+- `params/fanNames`: Array of custom fan names. Every fan name defaults to `""` if no custom name has been configured
+- `temps/names`: Custom names of the heaters. This is `""` for every heater that does not have a custom name
+- `coldExtrudeTemp`: Minimum temperature for extrusions
+- `coldRetractTemp`: Minimum temperature for retractions
+- `compensation`: Current type of bed compensation. May be either `Mesh`, `n Point` (where n is the number of probe points), or `None`
+- `controllableFans`: Bitmap of fans that are user-controllable. This excludes thermostatic fans
+- `tempLimit`: Maximum allowed heater temperature of the heater protection items. This is used for scaling the temperature chart on the web interface
+- `endstops`: Bitmap of currently triggered axis endstops
+- `firmwareName`: Name of the firmware **deprecated - see config response**
+- `firmwareVersion`: Version of the firmware **deprecated - see config response**
+- `axes`: Number of visible axes
+- `totalAxes`: Number of total axes
+- `axisNames`: Letters of the visible axes
+- `volumes`: Total number of supported volumes
+- `mountedVolumes`: Bitmap of mounted volumes (1 = drive 0, 2 = drive 2, ...)
+- `name`: Hostname of the machine
+- `mcutemp` (optional): Minimum, current, and maximum MCU temperatures
+- `vin` (optional): Minimum, current, and maximum input voltage
+- `v12` (optional): Minimum, current, and maximum voltage on the 12V rail
+
+## Print Status Response (Type 3)
+
+This status response type provides extra details about the file being processed. The format is
+
+```
+{
+	...
+	"currentLayer": 0,
+	"currentLayerTime": 0.0,
+	"extrRaw": [],
+	"fractionPrinted": 0.0,
+	"filePosition": 0,
+	"firstLayerDuration": 0.0,
+	"firstLayerHeight": 0.00,
+	"printDuration": 0.0,
+	"warmUpDuration": 0.0,
+	"timesLeft": {
+		"file": 0.0,
+		"filament": 0.0,
+		"layer": 0.0
+	}
+}
+```
+
+where the fields are:
+
+- `currentLayer`: Number of the current layer being printed
+- `currentLayerTime`: Time of the current layer
+- `extrRaw`: Total amount of extruded filament without extrusion multipliers applied. This is useful to estimate the print progress
+- `fractionPrinted`: Fraction of the file printed on a scale of 0.0 to 100.0. This equals `filePosition / fileSize`
+- `filePosition`: Byte position of the file being printed
+- `firstLayerDuration`: Duration of the first layer or 0.0 if unknown
+- `firstLayerHeight`: Height of the first layer
+- `printDuration`: Total print duration (excluding pause times) 
+- `warmUpDuration`: Time needed to warm up the heaters
+- `timesLeft/file`: Estimation for the time left based on the file consumption
+- `timesLeft/filament`: Estimation for the time left based on the filament consumption
+- `timesLeft/layer`: Estimation for the time left based on the layer times
+
+## Configuration response
+
+In addition to the responses above, the config response provides values that are not expected to change unless the machine is reconfigured.
+Note that a user may choose to reconfigure the machine at any time. The config response comes in the following format:
+
+```
+{
+	"axisMins": [0.0, 0.0, 0.0],
+	"axisMaxes": [220.0, 200.0, 180.0],
+	"accelerations": [1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0],
+	"currents": [800.0, 1000.0, 800.0, 1000.0, 800.0, 800.0, 8000, 800.0],
+	"firmwareElectronics": "Duet 3 MB6HC",
+	"firmwareName": "RepRapFirmware",
+	"boardName": "MB6HC",
+	"firmwareVersion": "3.0beta12+1",
+	"dwsVersion": "1.24",
+	"firmwareDate": "2019-11-05b1",
+	"idleCurrentFactor": 35.0,
+	"idleTimeout": 30.0,
+	"minFeedrates": [10.0, 10.0, 0.5, 0.33, 0.33, 0.33, 0.33, 0.33],
+	"maxFeedrates": [250.0, 250.0, 3.0, 60.0, 60.0, 60.0, 60.0, 60.0]
+}
+```
+
+The following fields are reported:
+
+- `axisMins`: Minima of the visible axes
+- `axisMaxes`: Maxima of the visible axes
+- `accelerations`: Accelerations of the drives
+- `currents`: Configured motor currents
+- `firmwareElectronics`: Name of the firmware electronics
+- `firmwareName`: Name of the firmware (usually RepRapFirmware)
+- `boardName` (optional): Short name of the board, only applicable for Duet 3. May be `MB6HC` for Duet v0.6 or `MBP05` for the Duet v0.5 prototype
+- `firmwareVersion`: Version string of the firmware
+- `dwsVersion` (optional): Version of the DuetWiFiSocketServer (only Duet WiFi)
+- `firmwareDate`: Indicates when the firmware was built
+- `idleCurrentFactor`: Motor currents are reduced by this factor when the motors are idle
+- `idleTimeout`: Motor current reduction is performed after this time in seconds
+- `minFeedrates`: Minimum feedrates of the drives
+- `maxFeedrates`: Maximum feedrates of the drives
diff --git a/src/GCodes/GCodes.cpp b/src/GCodes/GCodes.cpp
index 93732629..619363a0 100644
--- a/src/GCodes/GCodes.cpp
+++ b/src/GCodes/GCodes.cpp
@@ -1455,7 +1455,7 @@ bool GCodes::LoadExtrusionAndFeedrateFromGCode(GCodeBuffer& gb, bool isPrintingM
 	}
 
 	// Zero every extruder drive as some drives may not be moved
-	for (size_t drive = MaxAxes; drive < MaxAxesPlusExtruders; drive++)
+	for (size_t drive = numTotalAxes; drive < MaxAxesPlusExtruders; drive++)
 	{
 		moveBuffer.coords[drive] = 0.0;
 	}
@@ -2184,9 +2184,9 @@ void GCodes::FinaliseMove(GCodeBuffer& gb)
 		segMoveState = SegmentedMoveState::active;
 		gb.SetState(GCodeState::waitingForSegmentedMoveToGo);
 
-		for (size_t drive = MaxAxes; drive < MaxAxesPlusExtruders; ++drive)
+		for (size_t extruder = 0; extruder < numExtruders; ++extruder)
 		{
-			moveBuffer.coords[drive] /= totalSegments;							// change the extrusion to extrusion per segment
+			moveBuffer.coords[ExtruderToLogicalDrive(extruder)] /= totalSegments;	// change the extrusion to extrusion per segment
 		}
 
 		if (moveFractionToSkip != 0.0)
diff --git a/src/Movement/DriveMovement.cpp b/src/Movement/DriveMovement.cpp
index 76cd9294..046bed8d 100644
--- a/src/Movement/DriveMovement.cpp
+++ b/src/Movement/DriveMovement.cpp
@@ -317,7 +317,7 @@ bool DriveMovement::PrepareExtruder(const DDA& dda, const PrepParams& params, fl
 
 void DriveMovement::DebugPrint() const noexcept
 {
-	char c = (drive < MaxAxes) ? reprap.GetGCodes().GetAxisLetters()[drive] : (char)('0' + LogicalDriveToExtruder(drive));
+	char c = (drive < reprap.GetGCodes().GetTotalAxes()) ? reprap.GetGCodes().GetAxisLetters()[drive] : (char)('0' + LogicalDriveToExtruder(drive));
 	if (state != DMState::idle)
 	{
 		debugPrintf("DM%c%s dir=%c steps=%" PRIu32 " next=%" PRIu32 " rev=%" PRIu32 " interval=%" PRIu32
diff --git a/src/Platform.cpp b/src/Platform.cpp
index 77773272..8b1dba6a 100644
--- a/src/Platform.cpp
+++ b/src/Platform.cpp
@@ -493,7 +493,7 @@ void Platform::Init() noexcept
 		axisDrivers[axis].numDrivers = 0;
 	}
 
-	// Set up extruders
+	// Set up default extruders
 	for (size_t extr = 0; extr < MaxExtruders; ++extr)
 	{
 		extruderDrivers[extr].SetLocal(extr + MinAxes);			// set up default extruder drive mapping
@@ -2243,7 +2243,7 @@ bool Platform::WriteAxisLimits(FileStore *f, AxesBitmap axesProbed, const float
 
 	String<ScratchStringLength> scratchString;
 	scratchString.printf("M208 S%d", sParam);
-	for (size_t axis = 0; axis < MaxAxes; ++axis)
+	for (size_t axis = 0; axis < reprap.GetGCodes().GetTotalAxes(); ++axis)
 	{
 		if (IsBitSet(axesProbed, axis))
 		{
diff --git a/src/Version.h b/src/Version.h
index b4776e9d..3cb9d716 100644
--- a/src/Version.h
+++ b/src/Version.h
@@ -20,7 +20,7 @@
 #endif
 
 #ifndef DATE
-# define DATE "2019-12-14b3"
+# define DATE "2019-12-14b4"
 #endif
 
 #define AUTHORS "reprappro, dc42, chrishamm, t3p3, dnewman, printm3d"