VISA Timeout error

[yg-cci]

I am very new to using VISA library, hopefully someone can point me to the right direction.

I have an application (Visual Studio 2013, vb.net) that  is used to control fiber optic switches via serial, utilizing USB-Serial converter. Everything is working the way it is supposed to when I try to communicate with device using exsisting library.

I am trying to evaluate NI VISA library(VISA.COM 5.7) to replace my current one.

When I try to access my device using VISA by sending *IDN? , i get VISA timeout error.

However, if i access my device using current library and then again using VISA i do get a proper response.

This behavior is device specific. If I use the same program and try to communicate with other devices using VISA i do get a proper response.

The device is LightTech Switch LT3000.

Thanks in advance for any suggestions.

[Albert.Geven]

Maybe that device uses another type of end of message sign. Could be cr or lf or both. I would try all combinations.