VISA Function Hangs If I Use Third-Party USB Serial Adapters

Updated Aug 31, 2018

Reported In

Software

  • LabVIEW

Driver

  • NI-VISA

Issue Details

VISA Read/Write function hangs if I use third-party USB serial adapters. Why this happens? Is there any way to fix this problem?

Solution

As written in the document about third-party USB serial adapters, some USB-to-serial adapters do not support asynchronous I/O. VISA functions use asynchronous mode as default, this causes hang up when read/write functions are called.
You can avoid this behavior by selecting Synchronous in Synchronous I/O mode as shown below, or using 'Byte at Port' to specify the number to read.

 

WAS THIS ARTICLE HELPFUL?

Not Helpful