how many Command buffer in SIMOTION, it is three? or , the CPU different ,the  Command buffer different ?

at  the  program ,we use the " getcommandid , buffercommandid , getcommandidstate ..." to manager the command buffer ,is it right ? 

Each TO has it's own.

You can force to buffer commandId while calling a command. Then you can check status of that command. But you can't check directly which command is being executed. In simple words, you can't ask TO "what command are you executing now?". To achieve this functionality you have to program command tracking buffer yourself. So each thread which want to issue command to TO will write its commandId and command identifer to the buffer and buffer manager will check status of that commandId. Then you can ask the buffer manager what command is being executed at present. Big task anyway,

to do check witch command working in the buffer .

e.g. CAM is runing ,i via the command check it at the buffer .

does i can ?

Well, if you want to just check the current status of a TO, you can use its system variables.

Eg. an axis with a synchronous operation can be check against being synchronized, actual status of operation and type of synchronisation with system variables:

your_sync_op_name.syncState = YES/NO

your_sync_op_name.state = INACTIVE/VELOCITY_GEARING/GEARING/CAMMING

your_sync_op_name.synchronizingState = INACTIVE/WAITING_FOR_MERGE/WAITING_FOR_SYNC_POSITION

/WAITING_FOR_CHANGE_OF_MASTER_DIRECTION/SYNCHRONIZING_NOT_POSSIBLE

/SYNCHRONIZING

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