Delimiter based framing in /usp/config


I am trying to read RFID tags using RDM6800. I am able to setup /usp/config on my mangoh yellow as follows:

“frame_timeout”: 1,
“framing”: {
“delimiter”: [
“string”: false,
“uart”: “UART1”

Its because frame format is as follows:
{2, 10 ascii coded chars, 2 checksum bytes, 3}
14 bytes in total.

When I use the configuration setting as above following error is seen when the data is read:
“json array element is not a string”

Please see the screenshot.
Please let me know what is wrong in the setting