Unable to specify Protocol in as RTCM2

Q&A forumCategory: QuestionsUnable to specify Protocol in as RTCM2
cono44 asked 11 months ago

Any time I try to set the Protocol in as RTCM, the change will not stick and the option changes to None. I specify Protocol in as RTCM2, press “Send” and it instantly changes to “None”. Same behaviour with both UART1 and UART2

Does anyone know what might be causing this issue?


I’m also unable to disable SBAS. In UBX-CFG-SBAS setting the subsytem to Disabled and pressing send, instantly reverts it to Enabled.

replied 11 months ago

RTCM2 is an old protocol and only supported by older uBlox receivers, and in those only a small subset of the original standard, like 1, 3, 6 and 9 as I recall. Many of the beacon towers supporting this have also been decommissioned. Post SA this type of Differential GPS has generally been considered a waste of time and effort, with RTK predominating as the primary path to precision in the last 25+ years. None of the carrier based RTCM2 messages (18,19, 20,21, etc) have ever been supported or documented for use by uBlox. Avoid NTRIP mount-points providing such messages, use the RTCM 3.x mount-points instead, primarily those using MSM class messages.

When the receiver returns an ACK-NAK message it indicates that it does not like, and is rejecting, the settings/parameters you have furnished.

Via key methods CFG-SIGNAL-SBAS_L1CA_ENA = 0

replied 11 months ago

Thanks, it wasn’t out of choice, I was trying to connect to a ntrip service and that was the only protocol available.

1 Answers
Ardusimple Staff answered 11 months ago
Hi Cono,
u-center shows options that are not supported by the receiver. For example RTCM2 is not selectable as an option in ZED-F9P.
About disabling SBAS this is possible, make sure you also have the checkbox “configure” selected, otherwise the “enable” chechbox doesnt work.
replied 11 months ago


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