Hi Justin,
has this item been fixed? I have a similar issue. The JSON string from RUT955 "Modbus data sender" contains a lot of garbage from a previous modbus serial master configuration. See below, only the part in BOLD should arrive at Azure IoT Hub, the rest of the data is old and stuck. Since it forms invalid JSON this way we cannot interpret the data in the cloud.
It seems like the send buffer (%a string) is not cleared before a new MQTT message is composed.
Best,
Dirk
[{"ID":"5", "TS":"1616505154","ST":"1001","VR": 223.500000,224.070007]}]0.800003,50.000000,-53.910000,-59.520000,-41.320000,-0.000000,-10.333900,-3.401700,-8.505600,0.000000,-6.148100,-13.146700,-4.312400,0.000000]}]]10.549600,11.442900,0.000000,0.580100,0.281200,0.991300,1.000000,21.700001,391.145721,398.754181,393.044281,160.490005,22.697201,23.405600,36.451099,0.622675]}]4665]}]]