modbus_codec 0.1.4

Transport-agnostic Modbus RTU codec for Dart. Encode request frames and decode raw response bytes into typed values over BLE, serial, or TCP.

0.1.4

• Decoder rejects oversized read responses (byteCount > 250) instead of accepting out-of-spec data.
• Decoder validates the address range on write-multiple echoes (startAddress + quantity - 1 <= 0xFFFF).
• ModbusConvert.bit restricted to position 0..31 — positions ≥ 32 are silently wrong on Flutter Web (dart2js).
• ModbusConvert.scale throws on factors that overflow the result to infinity.
• Added Modbus exception code 0x07 (negative acknowledge) to ModbusExceptionCode.
• ModbusFrameException.toString() now includes the raw frame bytes for easier debugging.
• ReadBitsResponse.packedBitCount is now a derived getter (always equals values.length).

0.1.2

• Rewrote README and library doc for BLE/mobile audience — send/receive examples, plain-language tables, no protocol jargon.
• Added address-range overflow check: encoder throws when startAddress + quantity - 1 > 0xFFFF.
• ModbusConvert.combine32 now uses multiplication instead of bit-shift for correct behaviour on dart2js.
• Decoder enforces minimum write-response frame length (8 bytes) before decoding FC 05/06/15/16.

0.1.1

• Input validation for slaveId, address, and quantity limits on all function codes.
• ReadBitsResponse now returns all byteCount * 8 bits; caller slices to request quantity.
• Decoder throws ModbusFrameException on malformed frames instead of crashing.
• ModbusConvert guards for non-ASCII input, negative scale factor, and padToRegisters overflow.

0.1.0

Initial release.

• ModbusEncoder for building RTU request frames: read coils / discrete inputs / holding registers / input registers (FC 01–04), and write single & multiple coils / registers (FC 05, 06, 15, 16).
• ModbusDecoder for parsing RTU response bytes into typed responses (ReadRegistersResponse, ReadBitsResponse, WriteSingleResponse, WriteMultipleResponse), with optional CRC validation.
• Crc16Modbus — CRC-16/MODBUS compute, byte generation, and validation.
• ModbusConvert helpers: signed 16/32-bit, 32-bit register pairing with selectable word order, fixed-point scaling, and packed-ASCII encode/decode.
• ModbusDeviceException / ModbusFrameException for device-reported errors and malformed frames.
• Zero runtime dependencies; pure Dart.