回复： Differents between open csv file by mannually and program automatically?

[hoover95]

Dear great master

I haved been consfused by a problem deeply.
Why a csv file if already open can be detected by mannually. can't be detected by program automatically.

I verify this phenomenon by below procedure:

First:

 Execute <simple_ErrCode_modify_by_NI2.vi>  at both computer respectively.then open csv file mannually,thus two programs both can detect the csv file already

open. also can enter case5 and wait case5's loop.

Second:
 Compare with First produre.firstly,execute <simple_ErrCode_modify_open_csv_atloop1.vi> in one computer , Adding while loop  after open/creat/replace file ,thus

 can maintain csv file open all the time.
 secondly,execute <simple_ErrCode_modify_by_NI2.vi> in the other computer.I find that <simple_ErrCode_modify_by_NI2.vi> cann't enter case5.

  Through above,

 I confused that why program can detect csv file already open by mannually.
 cann't detect csv file already open by the other pragram open.
 
Why have thus two kinds of mechanism in labview .

  Can who great master help me and answer me .

mentioned program attached.

 Thanks earnestly.

[ranbin]

hi:

  I tried your VI with little change on my PC in Window7&LabVIEW 2013 platform,  however, no error and warning accured, the code remained 0 instead 5. Both the two VIs can get access to the  .CSV file at the same time

  Generally speaking ,a file can be read by two progress at the same time ,but can never be written at the same time ,unless a Timing-division mechanism is added .