Thanks, however I still don't think that's quite enough info for me to proceed.
I have no issue connecting / opening the device and getting a handle back.
Regarding your sample command:
"If using standard HID ... 2. write to device using open handled using device.write( [0x02, 0x04, 0x00] ). Note, first byte should be report id, it could change per device."
a few questions:
1- the first byte - 0x02 - should be the report id, it could change per device.
OK, so how do I know what value of report id I should be using for a given device?
2- what do 0x04 and 0x00 represent in this case
3- what does this command do, and how do I map it to https://developer.jabra.com/site/global/sdks/web/documentation/index.gsp
To ask another way, what data would I send in to device.write() to cause the 9540 phone to start ringing, and then stop?
What command would I issue to cause the device to go on/off mute?
When the device sends me a uint8array containing 4, 2, 0, how do I decode that using the information on this page: https://developer.jabra.com/site/global/sdks/web/documentation/index.gsp