$PQXFI Decode Please

IoT Modules MC/EM Series
1

Good Day!

I’m having difficulty finding a definition / decode for the $PQXFI sentence (Proprietary Qualcomm eXtended Fix Information) included in the NMEA stream on the COM port for the EM7355 module.

Is this published anywhere? Who can be contacted for additional information?

Thank you!

–
Sean

2

Hi,
$PQXFI is used to transmit Qualcomm eXtended Fix Information message…
Don’t have much information about this :frowning:

-Alex

3

Hi
I found it documented here - https://microchip.ua/simcom/LTE/SIM7500_SIM7600/Application%20Notes/SIM7500_SIM7600%20SERIES_NMEA_SPECIFICATION_V1.0.0.pdf

4

@roger That link is dead now. Do you know where else I could find the PQXFI documentation?

5

what module are you using?
why do you need to decode PQXFI?

I asked AI, and it replies

A typical $PQXFI sentence might look like:

$PQXFI,194825.0,3800.678484,N,12233.048527,W,-2.8,3.54,2.50,1.335A

This appears to contain:

  • UTC Time: 194825.0
  • Latitude: 3800.678484 N
  • Longitude: 12233.048527 W
  • Altitude or Speed?: -2.8
6

I’m using WP76xx and RC76xx modules.

I would like to get the horizontal accuracy from the GPS module. According to AI, the PQXFI message should contain this information

7

do you mean “HEPE, Horizontal Estimated Position Error”?
If yes, you should be able to get this value in AT!GPSLOC?

8

I would ideally like to retrieve this information via a NMEA string, and some googling suggests that the PQXFI message should contain the horizontal accuracy.

The HEPE value from GPS!LOC seems to be the root of the sum of the squares of the latitude and longitude errors, which is a crude estimate of horiztonal accuracy. Apparently GNSS modules can provide a more accurate estimate of horizontal accuracy

9

i don’t see PQXFI contains “horizontal accuracy”, but it should have "Velocity Uncertainty "

10

Google AI suggests it does contain horizontal accuracy, or rather horizontal uncertainty

11

i don’t see any “horizontal accuracy” in your link

12

Apologies, I meant to say Horizontal Uncertainty

13

Then what is the problem here?
Didn’t your link have shown such item?

14

The problem is that I would much prefer official confirmation or documentation to state that the PQXFI message does indeed contain the horizontal uncertainty, rather than relying on error-prone AI

15

Then you need to contact distributor
Personally I would say that field is HEPE, you might need to compare that field with at!gpsloc

16

Understood, thank you very much for your help!