Documentation
¶
Overview ¶
Package claiming implements the NMEA 2000 / ISO 11783 address claiming protocol (PGN 60928). It supports two modes: auto mode, where the claimer negotiates downward from a starting address on contention, and explicit mode, where contention is treated as a fatal error.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Claimer ¶
type Claimer struct {
// contains filtered or unexported fields
}
Claimer implements the NMEA 2000 address claiming state machine.
func (*Claimer) Address ¶
Address returns the currently claimed address. This value may change over time as contention is resolved or a matching Commanded Address is applied.
func (*Claimer) HandleAddressClaim ¶
HandleAddressClaim processes an incoming Address Claim (PGN 60928) from another device. source is the CAN source address of the competing device and name is its 64-bit NAME.
If the competing device claims our address:
- If our NAME is lower (we win), we re-broadcast our claim to defend.
- If their NAME is lower (we lose), auto mode tries the next available address downward; explicit mode surfaces a fatal error.
If the competing device claims a different address, the message is ignored.
func (*Claimer) HandleCommandedAddress ¶ added in v0.3.0
HandleCommandedAddress applies an ISO Commanded Address (PGN 65240) to this node. The caller is responsible for accepting the command only from a fully reassembled, nine-byte broadcast transport transfer.
A command is ignored unless its complete 64-bit NAME matches this node and the requested address is claimable (0-251). A real change resets automatic contention history, notifies the owner, and immediately broadcasts a fresh Address Claim from the commanded address. The returned bool reports whether a change was applied.
func (*Claimer) HandleISORequest ¶
func (c *Claimer) HandleISORequest()
HandleISORequest processes an incoming ISO Request (PGN 59904) asking for PGN 60928. It responds with our current address claim.
type Config ¶
type Config struct {
// Mode selects auto or explicit address claiming behaviour.
Mode Mode
// Address is the starting address in auto mode or the fixed address in
// explicit mode. Valid range is 0-251.
Address uint8
// Name is our device's 64-bit ISO 11783 NAME used for arbitration.
// Lower NAME values win contention.
Name uint64
// WriteFrame sends a CAN frame onto the bus.
WriteFrame func(can.Frame) error
// OnAddressChange is called when the claimed address changes, either while
// resolving contention or after a matching Commanded Address transfer. It
// may be nil if the caller does not need notifications.
OnAddressChange func(newAddr uint8)
// OnFatalError is called when an unrecoverable error occurs, such as
// address contention in explicit mode. It may be nil.
OnFatalError func(err error)
// Logger is used for structured logging of claiming activity.
// If nil, a no-op logger is used.
Logger *slog.Logger
}
Config holds the parameters needed to construct a Claimer.
type Mode ¶
type Mode int
Mode controls how the claimer responds to address contention.
const ( // ModeAuto starts at the configured address (default 251) and works // downward on contention until all addresses are exhausted, at which // point it falls back to address 254 (cannot claim). ModeAuto Mode = iota // ModeExplicit uses a fixed address and surfaces a fatal error if // another device with a lower NAME claims the same address. ModeExplicit )
Source Files