Frame Box

FrameBox

class canlib.kvadblib.FrameBox(db, messages=())

Helper class for sending signals

This class allows sending signals without worrying about what message they are defined in. It does this by binding a message and all its signals to the same canlib.Frame object.

Objects are created by giving them a Dbc database, and optionally a list of messages (either names or Message objects):

db = Dbc(...)
framebox = FrameBox(db, messages=('Msg0','Msg1'))

Messages can also be added after instantiation with add_message:

framebox.add_message('Msg0', 'Msg1')

Then setting signal values for any added message is done with:

framebox.signal('Sig0').phys = 7
framebox.signal('Sig1').phys = 20

Once all values are set, they can easily be sent via the channel channel with:

for frame in framebox.frames():
  channel.write(frame)

Any Framebox methods that return messages requires the message to have been added to the framebox, either with the messages constructor argument or with add_message. Likewise, any methods that return signals require the signal’s message to have been added.

add_message(message)

Add a message to the framebox

The message will be available for all future uses of FrameBox.message and FrameBox.messages, and all its signals will be available for uses of FrameBox.signal and FrameBox.signals.

The message argument can either be a message name, or a canlib.kvadblib.Message object.

frames()

Iterate over all frames of the signals/messages from this FrameBox

message(name)

Retrieves a message by name

Returns a BoundMessage that shares its Frame object with its child signals.

messages()

Iterator over all messages that this FrameBox is aware of

signal(name)

Retrieves a signal by name

Returns a BoundSignal that shares its Frame object with its parent message and sibling signals.

signals()

Iterator over all signals that this FrameBox is aware of

BoundMessage

class canlib.kvadblib.BoundMessage(message, frame)

A CAN data object that manipulates data through signals.

BoundSignal

class canlib.kvadblib.BoundSignal(signal, frame)

property is_enum

Whether this signal is an enum-signal

New in version 1.7.

Type

bool

property name

Signal’s name string

Type

str

property phys

Signal’s physical value

Type

int or float

property raw

Signal’s raw value

Type

int

property unit

Signal’s unit string

Type

str

property value

Signal’s value

If the signal is an enum-signal (i.e. the signal has a defined value table), then the enum name is returned if found, otherwise the signals raw value (raw) is returned. If the signal is not an enum-signal, the signals physical value (phys) is returned.

New in version 1.7.