System and method applicable to vehicles for communicating between data processing stations

摘要: An off-board diagnostic device (master station) communicates with a plurality of electronic control units (subordinate stations) applicable to vehicle. initializing command (INIT) is transmitted by the all via communication circuit. The master station (diagnostic device), then, transmits system call circuit select particular unit be communicated station. selected returns first echoback signal inform receipt command. Then, (parameter set command) perform predetermined operation for controlled obejct (e.g., vehicular engine). second in response station, successively at least two information signals unit, being related third and fourth each signal. At this time, bit contents are determined depending on whether respectively same as or logically opposite those commands.