HiLetgo RS485 SHT20 Temperature Humidity Sensor Module High Precision Temperature Humidity Monitor Transmitter Sensor Probe Compatible to Modbus with 1M Lead

Red wire is supply (+) Black wire is supply (-) Yellow wire is data(+) White wire is data(-) Relative addressing is fine unless/until the implementation is wrong. Frankly it's MUCH less time consuming overall to give the MB addresses in both absolute and relative terms, as is done in virtually all professional data sheets. Register 0 (relative) is defined by the Modbus standard as (read code x04) 30001 for input registers and (read code x03) 40001 for holding registers. Register 1 (relative) is 30002 or 40002 and so on. To clarify - in *absolute* addressing terms: Register 30002 = Temp in C x10 (divide by 10 for correct value) Register 30003 = Humidity % x 10 (divide by 10 for correct value) MB addr. node is register 40258, valid values 1-247 Baud rate is register 40259, valid values 9600, 14400, 19200. Temp. comp. is register 40260, valid values +/- 100 (i.e. +/- 10.0 deg. C) Hum. comp. is register 40261, valid values +/- 100 (i.e. +/- 10.0%) Thankfully, once you get past the derp, the sensor works just fine.

Works great. had just a little figure out to do. Most important is, it is 1-based addressing, not 0-based. Also, be sure to pull only 2 input registers, otherwise, it returns exception code. As others mentioned, first is temp in C, second is humidity and you need to scale down by 10.

Could not read values by plc, yet modscan reads values just fine, sure item is great, could not use with my plc though. OK so I have this reading in the PLC, was using read command 3 instead of 4. Will do some testing to determine accuracy.