Preferences don't include Electronic Hook Switch option

[Izzy8]

Obihai makes a nice IP phone, but needs real support.  I have a Plantronics Savi 720 and purchased the appropriate EHS cable.  I also purchased the EHS cable from Obihai.  I plugged everything in following the directions.  I have a "preferences" app (not User Preferences) with a different icon than the manual.  I don't see a selection where I can select the Electronic Hook Switch.  Any assistance is appreciated.

[SteveInWA]

You're looking in the wrong place.

Go to your OBiTALK dashboard on a web browser:  https://www.obitalk.com/obinet/pg/obhdev

Click on your OBi IP phone, and then get into OBi Expert Configuration.

Edit the EHS setting on that page, and submit your change.  My screenshot below shows the setting for my Jabra EHS headset; you'll choose Plantronics instead.  Note the audio gain settings below the EHS setting; you may need to fiddle with those, up or down a couple of dB, to get the optimal sound levels.