Hi,
Apologies for the delayed response. Please try using Cypress's USB Serial DVK and check whether you are facing the same issue.
If you are facing the same issue, you can try to configure your hardware in NI MAX and check whether the same issue occurs or not. To configure the hardware, follow the steps mentioned below:
1) Open NI MAX.
2) Expand Devices and Interfaces. Then select the COM port of interest.
3) Select Open VISA Test Panel. Under the Serial Setting tab, set a size of Transmit Buffer and click on the Set Size.
4) Now, in the Input/Output tab, input a supported command and select Write. Refer to your instrument’s user manual for supported commands.
5) The display window will show the Write Operation and Return Count. You can also confirm by checking No Error message in Return Data window.
Regards
