question

Mark Anderson avatar image
Mark Anderson asked

Failing to get GPS Data via Modbus

HI All

I'm connecting my CerboGX to a home automation system (Home Assistant) via Modbus. I can get a lot of the dat but the GPS is not working.


My config YAML says this:

- name: "GPS Latitude"

data_type: int32

unit_of_measurement: "deg"

slave: 100

address: 2800


- name: "GPS Longitude"

data_type: int32

unit_of_measurement: "deg"

slave: 100

address: 2802


The sensor shows up buy with unavailable. The Cerbo GX shows this:


ERROR "Error processing function code 3, unit id 100,

start address 2802, quantity 1, src 192.168.50.171: Error

finding service with device type gps at device instance 0"


I don't see a unit ID for the GPS service anywhere, so I'm using 100

I see this in Home Assistant but status is unavailable

'sensor.gps_latitude'

'sensor.gps_longitude'


Any ideas?

Thanks


Mark

Modbus TCP
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

elvis avatar image elvis commented ·

I dont thinks it going to be ID 100.

Venus has to see your GPS and then you can go into the services modbus and get the right id.

Did you plug a GPS into the Cerbo? NMEA? USB?

0 Likes 0 ·
1 Answer
xsilvergs avatar image
xsilvergs answered ·

@Mark Anderson

If i look under Device List > Settings > GPS > NMEA blah > Device at the bottom I see VRM instance, in my case it's 1.

This is using a Raspberry Pi and a USB GPS.

And from my Node-Red

screenshot-2024-02-02-092401.png


screenshot-2024-02-02-092401.png (54.3 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Modbus TCP Basics