bytes at serial port

[mahi108]

I tried even that sir the same problem is getting repeated . some time it is working perfectly and some time while testing again it wont work . what to do sir 

[PBP]

Hi,

I would like to know more about your VI and hardware you are communicating with. Are you using onboard serial port or virtual serial port hardware like USB to serial converter? What is your modbus hardware? Why are you repeatedly transmitting same modbus command and data to device in while loop?

Kindly describe your application.

Check actual number of byte written at serial port by VISA write function.