How can I troubleshoot if my LPU-400 is not connecting during calibration? (RBtec LPU-400 Calibration Software User Guide)

Answer

manuals.plus

Nov 21, 2025 - 01:39 PM

If you encounter issues with connecting your LPU-400 during calibration, follow these steps for troubleshooting as per the manual:

1. **Check LPU Serial Port Recognition:** When clicking "Serial Connect" and receiving the message "COULD NOT IDENTIFY LPU SERIAL PORT," follow these steps:

- Open Device Manager through a command prompt or the "Run" window by pressing Windows+R, typing devmgmt.msc, and clicking "OK."

- Look for unrecognized FT232 or USB Serial Port devices. If found, download the drivers from.

- After updating the drivers, the USB Serial Port should be recognized as a COM port with a number.

2. **Troubleshooting Noise on Sensor Cable:** If there is extreme noise on the sensor cable, follow these steps to identify and address the issue:

- Disconnect all sensor cables from the LPU board. If the noise disappears, it indicates the noise is from the sensor cable.

- If the noise persists, the issue may be related to the board, power supply, or grounding.

- Check for shorts between cable wires, loose connections, or water in joints if the noise is from the sensor cable.

- If the noise is from the board, check for grounding issues, noisy power supply, or unshielded lead wire.

3. **Pulsating Noise on Sensor Cable:** If there is a pulsating noise on the sensor cable, follow these steps to troubleshoot:

- Disconnect all sensor cables from the LPU board. If the noise persists, it may be from the board or power supply.

- Connect a ground wire to the sensor cable to see if the signal stabilizes. If not, ground the negative (-) of the DC power.

4. **Issue with Power Supply:** If there are issues with the power supply, follow these steps:

- Lower the voltage to 12VDC if it's different.

- Test the system with a 12V battery to isolate the noise source.

- Ground the negative terminal of the DC voltage at the LPU board location to a true ground.

5. **Faulty CPU or Main Board:** If the above steps do not resolve the issue and the signal indicates a faulty main board or CPU, contact RBtec for further assistance.

By following these troubleshooting steps, you can address common connectivity issues and noise disturbances during the calibration process of your LPU-400 outdoor security solution.