- Replace P1-P6 rational transfer function with factor/offset model for bench params - Add explicit rx/tx direction flags in bench XML configuration - Add T.Tank (BenchTemp) and P2 (AnalogSensor2) to temperature/pressure display - Apply SensorConfiguration calibration to pressure channels, fix empty sensors.xml fallback - Add live value labels to flowmeter charts - Hide pump live values and PSG encoder standalone label - Add K-Line connection state model, improve KWP service and status displays - Restructure .claude/skills into subdirectory format Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
1.7 KiB
1.7 KiB
VP44 Protocol Reference
Quick reference for hardware protocol constants used in HC_APTBS. Consult this before modifying any protocol-related code.
DFI encoding (EEPROM address 0x0044 on VP44 ECU)
Read (raw byte → DFI value):
dfi = (sbyte)raw * 3.0 / 256.0
Write (DFI value → raw byte):
raw = (sbyte)((dfi * 256.0f) / 3.0f)
// If raw == 0, use 1 — the ECU rejects zero
Checksum:
checksum = (byte)(0 - (byte)rawValue)
IIR low-pass filter (PcanAdapter.PassFilterUpdate)
result = Math.Round(prev + alpha * (value - prev), 4)
Used to smooth CAN bus sensor readings. The alpha coefficient controls responsiveness vs. noise rejection.
OEM legitimation (PcanAdapter.Connect)
token = (20120378UL << 32) | 21200UL
Sent as a CAN frame to authenticate with the bench controller. Without this, the bench ignores all commands.
K-Line / KWP timing
Inter-byte delay (KW1281Connection.SendPacket):
Thread.Sleep(5) // after each byte — KWP protocol requirement, NOT a workaround
5-baud slow-init (KwpCommon.WakeUp):
- Bit-bangs the ECU address at 5 baud on the K-Line
- Sleep durations in WakeUp are protocol-mandated — do not change
Session lifetime:
- One
FtdiInterfaceopen/close per KWP operation - ECU expects a fresh session per dialog — do not pool connections
CAN bus (PCAN-Basic, 500 kbps)
- Channel:
PCAN_USBBUS1 - Baud:
PCAN_BAUD_500K - Read thread polls with
Thread.Sleep(2)inDrainMessageQueue(known debt)
Caution
Do not change any of these values without understanding the hardware protocol specification. Incorrect values can cause ECU communication failures or bench malfunction.