State Machine

State Machine是一个在工控中常用的程序构架。adeStateMachine 封装于LVOOP Class，不但提供常用的功能，而且有像延时，循环等高级功能，更重要的一点是它支持异步程序操作（Asyncronized Operation）。这些功能在工控中常用，因此使用这样的程序结构和这个State Machine就可以基本上满足90%以上的应用场景。在我们20年的工作经验中，首先想到的就是使用这个。

更重要的一点是这个使用adeStateMachine的结构还具有可扩展功能，因此几乎百分百的程序开始使用的都是这个结构。我们将在后面介绍如何在这个结构上进行扩展，使程序无限制的扩大，使多个人可以同时为一个程序工作。目前让我们先熟悉这个使用adeStateMachine 的程序结构吧。请下载源程序，它包含使用说明书，范例，模板等。

Download link: files.cnblogs.com/files/adetech/adeStateMachineBasic.zip  (adeStateMachineBasic.zip)

 

adeStateMachine and adeScriptEngine

The state is written in the native LabVIEW OO and it resembles JKI’s state machine, but it has a lot more power. The package comes with a sample architecture main vi which is powerful enough and therefore can be used as the starting point for many applications.

adeScriptEngine is inherited from adeStateMachine.  It has full features of the state machine and it has more.  It tends to load a script from a file together with instructions to users and it has more program flow control such as “goto”.

Object Name	adeStateMachineBasic   Command>>parameter Multiple commands are to be separated by carriage return // can be used to comment out a command line The main loop has to have an “Idle” case (default) When there is an error, state case = Error Handler Timeout should NOT be -1 if the full set of build-in commands are to be utilized
Methods	INIT	To be called once and input startup states
	GetCommand	Get the current command and parameter from the object
	AddCommands	Push multiple commands into the object, can be on top of the queue or/and appended to the end
Internal Commands	ade_Clear	Reset the object and then the command queue Used to stop all command execution It does not clear Commands associated to ade_Lock
	ade_Dwell>>time	Program will stay on this command for given period of time.  The timeout should not be 0 to use it.  Actual dwell time is a little more than the given.
	ade_asynDwell>>time	This command should always be used in pair: ade_asynDwell>>1000 command ….. ade_asynDwell   Kick off dwell timer but continue to run commands followed.  Program will evaluate the elapsed time at the second ade_asynDwell command then wait or continue
	ade_Pause>>timeout	It is normally used to pause the program and wait for an event where ade_Continue is called to continue the program flow.  timeout <= 0 is equivalent to 2 hours.   If timeout occurs, program goes to Error Handler with parameter = ade_Pause_Timeout.  This should be handled in customer program accordingly.   This command can also be used to pause a script or sequence it is running.  Use ade_Continue to resume program flow.
	ade_Continue	This is used to remove ade_Pause or ade_Dwell to resume program flow.
	ade_Lock>>Option	When Lock is on, the state machine will not register any command except specified Exception commands and internal command starting with “ade_”.   Option = 0:  Unlock Option = 1:  Lock Option = cmd1,cmd2,…  :register exception commands   ade_Clear will clear the lock but not exception commands.   This is useful when the program is running a sequence, at which time, program does not want to be disturbed by some manual commands.
	ade_Log>>Option	Option = 0: Do not log Option = 1: Do log Option = -1: Delete the log file   Log file is adeLog.txt in user/tmp directory.  This logging facility is extremely useful for debugging purpose, so it should always be turn on until formal software release.