Common issues and solutions for systems that combine GPS and INS technologies.
Inertial Labs offers various GPS-integrated systems, such as the INS, MRU-P(D), and WS-PD. This article aims to provide details on troubleshooting for users’ most common errors with these devices.  We encourage users to read their device’s latest Interface Control Document (ICD) and Graphical User Interface (GUI) manual for further information. These documents are available on the USB supplied with every order and can also be obtained by contacting IL Support, specifying the device serial number.
Start-Up Issues
Users are strongly encouraged to operate their devices using the cables, converters with the latest drivers, and power supplies provided by Inertial Labs. If you encounter issues using custom cables, try the same setup using IL cables. This determines whether the GPS-Integrated Systems need compatible equipment or if there are further issues with your unit.
At start-up, the device will initialize (solid yellow LED for a few seconds) and then proceed into idle mode (solid red LED) or, if configured for auto-start, data output mode (solid green LED). Note that Windows sometimes treats traffic on a newly created serial port as a mouse, which can lead to erratic pointer behavior. Disconnect the USB-to-Serial converter from the PC and device to solve this. Then, reconnect the USB port so that Windows does not capture any traffic on the port with the serial mouse driver. Finally, reconnect the converter to the device and proceed as usual.
Communication Issues
To send and receive commands, the GPS-integrated system should be:
- adequately powered and remain idle, indicated by a red LED.
- connected to the appropriate COM port at the correct baud rate.
If the device is powered, but the device LED stays off, ensure the device receives the correct voltage to operate. If the LED is green after initialization, the device is in AutoStart mode and should be stopped before the user can send commands. If using the GUI, enter the Test Options menu and select the COM number corresponding to COM1 on the device, the correct baud rate, and the Allow Auto Start checkbox. Click OK and then stop the device. If communicating directly to the device, send the stop command.
Parameter and Software Issues
Ensure the parameters loaded onto the device match the serial number printed on the unit. Each device has a unique set of parameters and must not be loaded onto other units. Additionally, IL encourages users to use their devices’ latest GUI software and firmware. However, in cases where this is impossible, use the GUI version corresponding to the firmware loaded onto your unit. Note that using outdated software to load parameters may cause issues.
The firmware update process is sensitive and requires a constant and reliable power source. If done incorrectly, the device may become corrupted. In this case, contact our Support Team to recover your device.Â
Unit Status Word Troubleshooting
The USW provides information on the state of your device. The low byte (0-7) indicates a failure or information, and the high byte (bits 8-15) shows a warning or information. A bit with a value of zero indicates regular operation with no errors. See the table below otherwise:
Byte | Bit | Parameter | Solution |
Low | 0 | Initial Alignment Failure | Ensure the device remains static during initial alignment or set this time to zero seconds. |
1 | Software Failure | See the notes below. | |
2 | Gyroscope Failure | See the notes below. | |
3 | Accelerometer Failure | See the notes below. | |
4 | Magnetometer Failure | See the notes below. | |
5 | Electronics Failure | See the notes below. | |
6 | GNSS Receiver Failure | See the notes below. | |
7 | Currently Performing On-the-fly Calibration | This is NOT a failure or warning but provides the user with calibration information. | |
High | 8 | Insufficient Power Supply | Ensure the voltage is within range. Note it is best practice to use the power supply provided by IL. |
9 | Excess Power Supply | Ensure the voltage is within range. | |
10 | X-Angular Rate Out of Range | Limit movement in the x-direction for best performance. | |
11 | Y-Angular Rate Out of Range | Limit movement in the y-direction for best performance. | |
12 | Z-Angular Rate Out of Range | Limit movement in the z-direction for best performance. | |
13 | Exceeded Magnetic Field Threshold | Remove objects with magnetic interference from the surrounding device area or perform magnetic calibration. | |
14 | Environmental Temperature Out of Range | Limit device exposure to excessive heat or cold as much as possible. | |
15 | Successful On-the-fly Calibration | This is NOT a failure or warning but provides the user with calibration information. |
If bits 1-6 indicate a failure, perform the following steps:
- Restore the device’s default factory parameters using the GUI (Parameters menu -> Open Parameters… -> Select corresponding *.prm file -> Click Load Parameters). Make sure to power cycle the device to apply all changes.
- Perform a device self-test in the Run menu of the device’s GUI to see if the issue is fixed.
- Contact IL Support for the latest firmware and GUI. To proceed appropriately, follow the team’s instructions.
LED Status Indicators
In addition to the USW status, the device LED behavior shows possible issues. A blinking yellow LED that lasts for five seconds indicates a parameter-related issue. In this case, users can try to restore factory parameters to fix the problem. A red LED blinking for five seconds shows an error in the IMU initialization. The device has a hardware error if the LED blinks red or yellow for over a few seconds. In these cases, users should contact support@inertiallabs.com for assistance.
Further Questions
Inertial Labs prioritizes customer satisfaction, offering extensive technical support and customization services to meet its clientele’s varied demands. For questions on the topics discussed in this guide, contact support@inertiallabs.com.