Step 3. Place the DPU-550 in Program Mode

The tact switch next to the USB connector on the DPU-550 is used to place the DPU-550 in program mode so that it can receive the binary image from SAM-BA.  To do this, first disconnect all of the external cables as well as the power supply from the DPU-550.  With the tip of your finger or a pointed instrument, hold down the tact switch as you plug the power supply back into the DPU-550.  Keep the tact switch held down for 15 seconds and then release it.  Disconnect the power supply and you should be ready to proceed.