communicating with a sensor through SDI12 protocol

[awayllace]

Has anybody been able to read a sensor that communicates through SDI12 protocols? Any leads would be very useful.

This is what I have:

Sensor: ATMOS 14 from Meter.com. The sensor specifies compatibility with any data acquisition system capable of 3.6- to 15.0-VDC power and serial or SDI12 communication.

Data acquisition: NI USB-6008   (it is unclear to me if this datalogger works, it does have digital I/O channels so it seems it should work)

I tried connecting it to NIMAX following the steps below:

Connecting Digital Input Signals to a DAQ Device - National Instruments (ni.com)

But I basically only see the image below regardless of what is connected where in the datalogger

I tried running the program "Digital continuous input.vi" from the examples provided in LABVIEW2018, and it just gives me an error.

I know many sensors communicate through SDI12 protocols so I am hoping someone did something similar before?

The integrator guide of my sensor provides commands to interact with the sensor, for example ai! for identification, etc.

Thank you!

[santo_13]

USB-6008 is a low-cost entry-level DAQ and its features are limited. One such limitation is that the Digital Input/Outputs can operate only in a static timed manner, this means that the state transitions cannot be precisely timed. You might realize that any Digital Protocol requires precisely timed digital transitions to communicate which is not possible on this DAQ.

SDI12 spec - https://sdi-12.org/current_specification/SDI-12_version-1_4-Jan-30-2021.pdf

I am not optimistic that you will be able to implement the protocol with software timed DIO.

There is no ready-to-use device from NI that supports the SDI12 protocol. My google search revealed that this protocol is somewhat similar to RS232/UART, you might want to investigate more and find a dongle that might support SDI12.