Study on Formal Modeling and Safety Verification of Train-to-Train Communication

Table 2

Actions description in system mode transition model.

Action	Description	Action	Description
inichk	Self system is in initialization check	sndBldTracReq	Send build tracing request message
inisysOK	The initialization check of self system is OK	bldTracReqTimeout	Timeout for built tracing request
inisysBad	The initialization check of self system fails	rcvBldTracAns	Receive build tracing answer message
sndReqTrain	Send request message to trains	checkTracCond	Check the condition of tracing mode
rcvFdReqTrain	Receive feedback message from trains	tracCondisOK	Tracing condition is still satisfied
checkTrainID	Check train ID	tracCondNotOK	Tracing condition is unsatisfied
rcvReqTrain	Send request message to trains	setTracMode	Evaluate the train mode
reqTraintimeout	Timeout for request message	selfFixBlock	The mode is set fixed blocked mode
trainAlarm	Train alarm for error	selfTracingMode	The mode is set tracing mode
sndITS	Send error message to central ITS	sndDismissTracReq	Send request message for dismissing tracing
isTrainPos	Evaluted train postion	rcvDismissTracAns	receive request message for dismissing tracing
trainisFront	Train is in front	dismissTracReqtimeout	Timeout for tracing request message
trainisBack	Train is behind