@t310096 if you changed the communication parameters you will need to reset them as explained in the user manual: http://support.robotiq.com/display/RUI/4.+User+Interface+Description
Recovery Procedure : If you have changed the ModbusRTU communication parameters of your gripper, it won't be detected during the "Search for Devices". To recover it, select the COM port, press the button "Recover Device" and power cycle your gripper. The program will attempt during 10 seconds to boot the device with its default communication parameters.
When I use the user interface software to change baud rate(115200 -> 9600), I can't connect the 2-finger 85 gripper anymore. I follow troubleshooting of the manual to reinstall the driver, but it's useless. (Solid red, no fault, but Gripper is not communicating. Not lit, no USB communication.) How to solve it?