Through labview to read PLC .It is not return any value to me,after resolve error 1073807246.

[夏蝉]

I made a program about use VISA to read PLC.When I run the program it give me "the error -1073807246 the resource is valid,but VISA cannot currently access it". Through this BBS I know another program has control over the serial port.I close the other program,but the program still not normally!

I send the data to PLC.It is not return any value to me.and it no error.

Please tell me why,and give me the solution.

ps:I through another software to test,it is well.I checked the VISA configure ,it is right!

The accessory is my program.Please help me to check if my program is wrong.