Hello Thierry07,
Thank you for contacting National Instruments.
The first thing would be to test your device locally. You have a quick start section in this document that might help you. This will be possible only if your devide is equipped with the front panel display according to the same documentation.
If this is not the case, interacting remotly with your ESP requires the correct Software documented in the section "Software Utilities". Could you give us more information about your configuration (OS, software used...)?
Then when you will be able to communicate, you'll need to use one of the command list listed in the "Command Summary" part.
If your hardware is not working correctly, you should directly contact the manufacturer of your product: Newport.
I think they will be much more quicker to answer and will have the experience to resolve your issue.
Regards.
PS: il existe un forum francophone ici si cela vous intéresse: French Forum