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ZED-F9P Moving Base RTCM Messages not recognized

Q&A forumCategory: QuestionsZED-F9P Moving Base RTCM Messages not recognized
shannonp asked 3 weeks ago
Hi Everyone!
I am trying to achieve a moving base rtk solution with the ZED-F9P. From my understanding, I should be able to set RTCM messages as an output on a uart bus and then use a wire to connect the uart on the rover. I have set the rover to “listen” for the RTCM messages on the uart line and I have confirmed they are being sent with an oscilloscope. However, the rover is not recognizing the messages as being sent. The RTCM-status message is indicating that none have been received and, by extension, none have passed checks. Has anyone seen this before or know how to fix it? Thanks! 
replied 3 weeks ago

>>Has anyone seen this before or know how to fix it?
We have recurrent problems here with lack of specificity and workable detail. Seen a lot of people with a lot of problems.
Scoped which pin? Saw what? Bit timing/framing looked good? Spliced into a USB-to-CMOS Serial you could see packet data?
On the Arduino Rail RX2 is an OUTPUT (ZED.UART2.TX)
In a dual arrangement of RTK2B shields, RX2 of the primary (moving base) would connect to TX2 of the secondary (rover). If the signal has a lot of ringing, perhaps use a 27R or 33R series resistor in place of a wire.
IOREF would need to establish the IO voltages,and the boards would need to share a common ground.
UART2 can be set for RTCM3 IN/OUT, with only the primary outputting the messages.
Baud rates would need to be common.
UBX-MON-IO/COMMS/RXBUF/TXBUF reporting might give perspective on whether signals are seen as noise or unknown data.
Watch for a XBee radio mixing conflicting data into ZED.UART2.RX, a quiet serial signal is HIGH by default. Scope the input to the ZED if you can trace the signal.

1 Answers
Ardusimple Staff answered 3 weeks ago
  1. Which boards do you have?
  2. How are moving base and rover UART pins connected?
  3. Do you have GPS antenna outdoors or indoors?