Yes, you can use an RS232 Serial to Serial or a USB to RS232 cable to connect directly from your PC to the M1’s RS232 Serial Port. It is a straight through connection (Pin 2 to 2, Pin 3 to 3 and Pin 5 to 5, see page 7 of the M1 Installation Manual). In Windows Device Manage check to see what COM Port number Windows has assigned to your cable and then check the Baud Rate or the Port Speed — it should be 115200 BPS. In ElkRP2 under Setup, Communications, use the dropdown for “Select the serial port to use for direct connections” to select the same COM Port number Windows assigned to your cable, click OK. Next click the Connection icon on the toolbar, On-site Local, select “PC Serial or USB to Serial Converter TO Device”