GNSS Performance Query on TracX-1b EVK with EC200U-CN

IoT Modules LTE Standard Module
1

Hi Team,

We are evaluating the GNSS functionality on the TracX-1b EVK based on the EC200U-CN module.

Module Details:

  • Module: EC200U-CN

  • Firmware Version: EC200UCNAAR03A09M08

  • External GPS antenna: 1575.42 MHz GPS antenna(gain-28dB typical,DC voltage-3.0 to 5v)

The following behavior was observed during testing:

  1. GNSS can be enabled successfully using:
    AT+QGPS=1

  2. GNSS status confirms that the engine is running:
    AT+QGPS?
    +QGPS: 1

  3. During indoor testing:

    • AT+QGPSLOC? returns +CME ERROR: 516.

    • No GPS fix is obtained.

  4. When the EVK is tested outdoors under open sky conditions:

    • AT+QGPSLOC? returns valid latitude and longitude coordinates.

    • GPS fix is acquired successfully.

  5. After moving the EVK back indoors, AT+QGPSLOC? again returns:
    +CME ERROR: 516.

Additionally, the initial GPS fixes obtained outdoors show some variation in latitude, longitude, altitude, and HDOP values before stabilizing.

We would like to confirm:

  1. Whether this indoor and outdoor GNSS behavior is expected for the TracX-1b EVK.

  2. Whether firmware version EC200UCNAAR03A09M08 has any known GNSS-related limitations or recommended updates.

  3. Whether the EVK supports both active and passive GNSS antennas and if any specific antenna recommendations are available.

  4. Whether there are any recommended GNSS configuration settings to improve the first-fix time and positioning accuracy.

Please let us know if any additional logs or information are required.

As if we want to integrate the EC200U-CN into our custom board we cannot check the outdoors so we need clarifications on this

Thanks and Regards,

2

Hi there,
Answering to your questions:

1.Whether this indoor and outdoor GNSS behavior is expected for the TracX-1b EVK.
A: based on my search, this TracX-1b EVK do support GNSS functionality. There is much difference in the GNSS behavior when testing indoor or outdoor.

It is preferred to test the GNSS functionality in outdoor environment. Please make sure there is a clear sky during the testing while antenna facing to the sky.

Please also take note on the antenna selection below:

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  1. Whether firmware version EC200UCNAAR03A09M08 has any known GNSS-related limitations or recommended updates.
    A: the release note on the newer version showing there is a Fixed the problem of no NMEA statements outputs if GNSS was restarted in the case of deleting GNSS firmware.

Attached the newer FW version: EC200UCNAAR03A17M08.zip

  1. Whether the EVK supports both active and passive GNSS antennas and if any specific antenna recommendations are available.
    A: please refer to Q1 answer.

  2. Whether there are any recommended GNSS configuration settings to improve the first-fix time and positioning accuracy.
    A: please refer to Q1.

If possible, you can also provide us the NMEA sentences for us to check on it.