CanKit.Pro.J1939Tp 1.2.3

CanKit.Pro.J1939Tp

SAE J1939-21 Transport Protocol (TP) for CanKit.Pro. Implements both flavors of the J1939-21 §5.10 transport service:

• TP.BAM (Broadcast Announce Message) — one sender pushes an up-to-1785-byte PDU to every node on the bus, no acknowledgement (FR-TP-030).
• TP.CM (Connection Mode: RTS / CTS / EndOfMsgAck / Connection Abort) — point-to-point, with block-size negotiation and end-of-message acknowledgement (FR-TP-031).

TP.DT (Data Transfer) frames carry the segmented payload for both flavors, sequence-numbered from 1 (FR-TP-032). Every session runs on its own actor-owned state and its own set of IDeadlines (T1, T2, T3, T4, Tr, Th — FR-TP-033), so multiple sessions can execute in parallel over the same physical bus (FR-TP-034/035) without interfering with each other.

The channel ships on nuget.org alongside the other CanKit.Pro.* L2/L3 building blocks. It re-uses:

• CanKit.Pro.RawCan — one ICanBusService per channel to demultiplex the TP.CM / TP.DT frames back out of the shared bus stream and to confirm outbound frames.
• CanKit.Pro.Actor — one IProtocolActor mailbox for single-writer session state.
• CanKit.Pro.Reliability — IDeadlineScheduler for T1/T2/T3/T4/Tr/Th, cancelled/re-armed on the actor's loop.
• CanKit.Pro.Addressing — J1939Id / J1939Pgn for composing the TP.CM (PGN 0xEC00) and TP.DT (PGN 0xEB00) 29-bit IDs.

Basic usage

using CanKit.Abstractions.API.Can;
using CanKit.Core;
using CanKit.Pro.J1939Tp;

// One bus, two nodes on their own source addresses.
using var bus = CanBus.Open("virtual://demo/0",
    cfg => cfg.SetProtocolMode(CanProtocolMode.Can20).Baud(500_000));

using var sender   = J1939Tp.Open(bus, sourceAddress: 0x01);
using var receiver = J1939Tp.Open(bus, sourceAddress: 0x02);

// TP.BAM: broadcast to every node.
await sender.SendBamAsync(pgn: 0xFECA, payload: new byte[100]);

// TP.CM: point-to-point with RTS/CTS/EOM.
await sender.SendCmAsync(pgn: 0xFECB, destinationAddress: 0x02, payload: new byte[300]);

var received = await receiver.ReceiveAsync();
// received.Pgn / received.SourceAddress / received.DestinationAddress / received.Payload

Coverage

Install

dotnet add package CanKit.Pro.J1939Tp

# plus a CanKit adapter for the hardware you actually talk to, e.g.
dotnet add package CanKit.Adapter.Virtual   # loopback, no hardware

Dependencies: CanKit.Abstractions, CanKit.Pro.Actor, CanKit.Pro.Addressing, CanKit.Pro.RawCan, CanKit.Pro.Reliability.

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.