CNT-91 via USB disconnecting after ":SYST:TALK ON" SCPI command

Hi everyone!

I am using NI VISA drivers to manage my lab tools via USB. If I am using FormattedIO interface everything is good excepting speed. Now I am trying to put my Pendulum CNT-91 counter to the "talk only" mode. But when I send the command "YST:TALK ON" my computer beeps warning me about disconnecting of my counter.

I am using CNT-90 programmer handbook and VISA documentation but I am failing again and again.

Please find my SCPI code below:

***

:CONFHAS (@2),(@1)

ISP:ENABLE OFF

:FORM REAL

:ARM:COUN 1

:TRIG:COUN 1

:INIT:CONT ON

YST:TALK ON

***

After this code computer beeps but in windows hardware manager counter does not disappear. So, after it I can not do something with device.

Do you have any advices for me?