I’m a first time user of Jrk controllers. Now I’m trying out the device number function, but it seems my jrk controller keeps ignoring the specified device number in the command. Here are the details of what I’m trying:
the jrk controller is connected to the PC via USB, with the device number set to the default 11
You are making the same mistake as the customer in the thread you linked to. Since you are trying to use the Pololu Protocol but did not clear the most significant bit of the command byte, the last two bytes of your command are a valid Compact Protocol command, and any jrk that sees that command will respond to it. Your command byte is 221 (0xDD) right now. To clear the most significant bit, you would decrease it by 128 to get 93 (0x5D).
It looks like you are trying to send a Set Target command. The jrk user’s guide specifies that the series of bytes you need to send for a Set Target command using the Pololu Protocol is: