L2 · Infrastructure Validated CAN IDs, J1939 PGN/NAME composition and decomposition

CanKit.Pro.Addressing¶

CAN-ID addressing helpers for CanKit (arc42 "Adressierungs- Helfer"; SRS FR-RAW-040/041): validated 11-bit/29-bit CAN ID construction, J1939 PGN/Priority/ PDU-Format/Source-Address composition and decomposition, J1939 NAME field accessors, and PGN classification helpers, as pure, dependency-free helper functions — no dependency on any other CanKit package.

Status: 1.0.0 – 1.2.3 are withdrawn from nuget.org — they were published as stable before the API had been reviewed. 1.3.0 will be the first release whose API is stable; until it is tagged there is no listed version to install, so the dotnet add package line below resolves nothing and the withdrawn releases come back only on an exact version pin. The public surface can still change until then. See Versioning.

This generalizes logic that previously only existed as one hard-coded case inside IsoTpEndpoint.CreateNormalFixed (a single fixed diagnostics PGN) into reusable helpers any protocol layer (ISO-TP, J1939, CANopen, ...) can call directly.

using CanKit.Pro.Addressing;

// Validated 11/29-bit ID construction (FR-RAW-040)
CanIdRange.ValidateStandard(0x7FF);   // ok
CanIdRange.ValidateStandard(0x800);   // throws ArgumentOutOfRangeException

// J1939: build a 29-bit ID from priority/PGN/source/destination
var id = J1939Id.ComposePgn(priority: 3, pgn: 0xFED9, sourceAddress: 0x17);

// J1939: decompose a received 29-bit ID
var fields = J1939Id.Decompose(id);
fields.Priority;            // 3
fields.Pgn;                 // 0xFED9
fields.SourceAddress;       // 0x17
fields.IsPdu1;               // whether PS is a destination address or a Group Extension
fields.DestinationAddress;  // null for PDU2 (broadcast-only) PGNs

// J1939: classify common PGNs and TP.CM BAM control bytes
J1939Pgn.IsRequest(0xEA00);                   // true
J1939Pgn.IsTransportCm(J1939Pgn.TpCm);        // true
J1939Pgn.IsBam(J1939Pgn.TpCm, 0x20);          // true; BAM is a TP.CM payload control byte

// J1939: compose/decompose a 64-bit NAME and compare address-claim priority
var name = new J1939Name(
    identityNumber: 0x155555,
    manufacturerCode: 0x5AA,
    ecuInstance: 0x5,
    functionInstance: 0x12,
    function: 0xAB,
    reserved: false,
    vehicleSystem: 0x35,
    vehicleSystemInstance: 0xA,
    industryGroup: 0x3,
    arbitraryAddressCapable: true);
var sameName = J1939Name.Decompose(name.Value);
J1939Name.CompareClaimPriority(name, sameName); // 0; lower unsigned NAME wins address claiming

CanKit.Pro.RawCan's CanIdFilter also gained an Overlaps(CanIdFilter other) method and ICanBusService.FindOverlappingFilterSubscriptions() (FR-RAW-041, Should): a diagnostic to catch misconfigured protocol instances whose ID-range/mask subscriptions were meant to be disjoint but overlap. Each hit comes back as a FilterOverlap naming the two subscriptions and the range of CAN IDs they share, so the report says where the collision is and not only that there is one.

Install¶

dotnet add package CanKit.Pro.Addressing

No dependencies beyond the .NET base class library.

Part of CanKit.Pro — higher CAN protocol layers built on top of CanKit, which is consumed as a NuGet package rather than forked.

License¶

MIT — see LICENSE. CanKit itself is a separate project licensed under Apache-2.0; see THIRD-PARTY-NOTICES.md.