As I suspected in that edit in my post. Those are multiple API receive packets. They start with each hex value 7E. To avoid this set the Coordinator to AT mode. But then you will not know from which module the data came from (if you have more than one transmitters).
This is what the API frames interpreter function of Digi’s XCTU NextGen progam returns:
RX (Receive) Packet 16-bit Address
7E 00 18 81 00 00 42 00 31 32 36 31 2C 33 2C 33 2C 33 2C 33 2C 33 2C 33 2C 0D 0A F5
Start delimiter: 7E
Length: 00 18 (24)
Frame type: 81 (RX (Receive) Packet 16-bit Address)
16-bit source address: 00 00
RSSI: 42
Options: 00
RF data: 31 32 36 31 2C 33 2C 33 2C 33 2C 33 2C 33 2C 33 2C 0D 0A
Checksum: F5
The Arduino Serial monitor, and Realterm in Ascii mode is able to show the comma seperated numbers, and the end-of-line and carriage-return codes in the stream. All that other garbage is just the header and Checksum of the packet displayed out-of sequence. This is the translation of the RF data line into Ascii characters. Looks familiar:
1261,3,3,3,3,3,3,
“show spoiler”
No, never seen it on the forum. And tried the tags the other day, but no go. Something to request to Sparkfun I guess. But the [ /code] tags do collapse the windows. But then other BBcodes for text formatting do not work in it.