ZED-F9R - Application note 
UBX-22035176 - R01  Contents  Page 26 of 30 
C1-Public   
 
Figure 20: u-center UBX-MON-SPAN showing the spectrum at the L1 and L2 bands 
A.4  Communications and protocols 
One reason that a fixed ambiguity is not achieved may be the corrections not being received or used. 
Figure  21  shows the  UBX-MON-COMMS  message  used for monitoring the traffic at the 
communication ports. When the receiver is outputting and getting corrections on UART1, the byte 
counter should be increasing for both the transmit and receive direction. If the protocol byte counters 
are not incrementing on the interface as expected, this could mean that either the protocol is disabled 
on the interface or the baudrate is incorrect. 
 
Figure 21: u-center UBX-MON-COMMS showing traffic count by interface and protocol 
If the data is arriving, the messages that are being used are shown in UBX-RXM-COR. Below is an 
example of SPARTN corrections being received. The “can handle”, “Used” and “Decrypted” shows that 
a software handler exists, whether the message can be used and whether the message was 
successfully decrypted.