Connect your KX2 via a KXUSB serial data cable to your personal computer.
Choose the serial port that is connected to your KX2. Click the down arrow to show the list of available serial ports and then select the port you have connected to your KX2. See Finding the appropriate serial port for a USB to Serial Adapter if you're using a USB to Serial Adapter and are not sure which port to choose.
Reopens the serial port and verifies that the KX2 Utility can communicate with your KX2 and determine its RS-232 speed.
If you change the KX2's RS-232 speed using the KX2 front panel CONFIG:RS-232 menu selection or by entering a KX2 command in the Command Tester, use this button to allow the KX2 Utility to discover the KX2's new speed.
Note: If the KX2 is already loaded with MCU firmware (as indicated by a VFO frequency in the KX2's LCD display), it should respond to Test Communications with an "Information" dialog indicating that the KX2 is running the "Main" program. The speed shown should match the KX2 CONFIG:RS-232 menu selection.
If the KX2 is in a "Boot Loader" state, as indicated by the letters "MCU LD" on the LCD display, the KX2 should respond to Test Communications with a "Warning" dialog that looks like this:
If the KX2 has a running MCU (as indicated by a valid VFO A display) and Test Communications results in this Warning dialog, the KX2 Utility is not communicating with the KX2.
A KX2 in its boot loader, modems, null modem cables, and defective serial cables can echo whatever is sent to them. The KX2 Utility cannot tell what device is attached without sending a block of firmware. If MCU firmware load fails on the first block (address x800), it is very likely that the communications cable is not correctly attached to your KX2, the cable is defective, or the wrong serial port has been chosen.