No satellites: antenna issues and interferring devices (road tax devices)

Title:

Recommended action for problem when «No satellites»: antenna issues or interfering devices (road tax devices).

Issue description:

There may be problems with the correct display of the GPS location (satellites = 0 or less than ~5).

Cause:

The reasons can be in physical damage to the external antenna(cable), also the cause of the problem can be deliberate and unintentional influences (including jamming) for the GNSS (GPS) module.

Actions:

to check the primary diagnosis, first of all, you need to send an SMS

SMSpassword coords

Answers to SMS with "GPS is not available" and "lat. 0.0000000, long. 0.0000000, alt. 0.0, sat. 0," also indicate a problem, since this indicates that the number of satellites (sat.) Is 0 and it is impossible to determine the current location.

Also important to check the number of satellites in history (analysis by coordinates) for several days including the day of the problem.

In the case when the number of satellites decreases to 5 -> 0, especially when moving and the presence of RPM or other sign that the ignition is on, this confirms the presence of a problem.

The problem of falling satellite signal (including to 0) is not related to software or tracker settings. Most likely there may be at least 2 reasons:
reason 1) If the external antenna of the device is damaged or if it is physically disconnected (permanent or for a certain period), a very similar situation will be observed when the number of satellites decreases and the tracker cannot determine its location, it freezes in the Trust Track system. According to the attached photo and in the history analysis by coordinates, you can see that quite often a decrease in the number of satellites to 0 occurs in motion (with RPM > 0), which can be indirectly determined by the voltage of the power source (when the car is working, the voltage is at the level of 27-29 Volts, when the car is parked and the engine is off - voltage is less than 26-25 volts).

reason 2) From practice, I can say that quite often the reason for the loss of a satellite signal in such situations was the use of third-party devices (even road tax devices) that were a source of electromagnetic waves, in fact they were sources of interference for the correct operation of the tracker. Most often these were FM modulators. Also often they could be plug-in voltage converters, when in a car they could be “powered” from the car’s on-board circuit and laptops or similar devices could be connected.

I draw your attention to the fact that ordinary standard devices, such as tablets, phones, chargers for gadgets, etc. they do not interfere or interfere with the joint correct use of devices.

Therefore, first of all, I recommend making sure that the vehicle does not use third-party devices that can be sources of significant interference. If disconnecting devices that may be a source of interference does not help to solve the problem, then I recommend organizing an inspection of the connections directly in the vehicle itself, it is important to make sure there are no problems with wiring or connections.

The client and our installers should be informed that if, when organizing a physical departure of our specialist to inspect the connections, if the problem is not associated with damage to the wiring and external antenna, then it will be necessary to move the tracker and its external antenna as far as possible from potential sources of interference, toll payment devices, etc.

Tools required to fix the issue

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Document#	No satellites - antenna issues and interfering devices (road tax devices)
Created By:	Viktar Konanau
On:	30/07/2021
Modified By:	Name Surname
On:	dd/mm/yyyy hh:mm:ss