try https://kb.netapp.com/support/index?page=content&id=1010551 that shows how to connect via plink.exe.
basically save plink and perfstat under c:\.
run from comand line c:\plink root@your_netapp_ip
enter your root password, accept if any the key to be saved on cache
you should be connected on your netapp, type ctrl-d to log off
comand line c:\perfstat.exe -f NetappIP -t 25 -i 10 -l root -S pw:PUT_YOUR_ROOT_PASSWORD > today.perfstat.out
t and i you can put any number suites you
hope this helps
Do you already tried the newest version of perfstat8 (from 2. November)?
This new version works much better.
Or feel free to try this tool if you still have problems: