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Reply To: Hydros 21 Gen 2 -9992 values

Home Forums Environmental Sensors Hydros 21 Gen 2 -9992 values Reply To: Hydros 21 Gen 2 -9992 values


    Hi Shannon,

    Thanks for your reply, and apologies for not replying sooner.  My replies to your message are in bold:

    1. Do you have one of the Meter ZSC bluetooth interfaces for setting and checking Meter Group sensors? They’re really handy testing and troubleshooting things like their CTD sensors, and for changing the SDI12 address.  – No I only have spare Mayfly boards to test this device.
    2. It would be important to know whether it’s the sensor that is reporting -9992 or if it’s what the Mayfly is saying. – I suspect there is some confusion between the data coming back from the sensor the -9999 code programmed in Modular sensors.  It seems strange that the temperature sensor works fine but not the others. 
    3. Do you only get that value when the sensor is plugged in to the Mayfly?  Does the Mayfly report -9999 for all 3 parameters when no sensor is connected? – Yes I get -9999 when no sensors are attached.
    4. Are you running a logging sketch or a simple test sketch? – I am running a logging sketch.  This sketch works perfectly for my other 9 sites. I will upload ‘d_simple_logger’ when I am next at the site to determine the raw information from the sensor.
    5. You could also try putting the SDI-12 address back to ‘0’ and then power the sensor and watch the serial DDI string it prints out, thus bypassing the SDI-12 libraries all together, which again can help determine if it’s a sensor issue or a Mayfly library issue. – Is there a sketch I could use for this, or is it as simple as setting the sensor power as ‘high’ and reading the output? 
    6. You should also disconnect all other external sensors from the Mayfly when troubleshooting communication issues because we’ve seen several instances of a CTD sensor losing partial or total communication with a Mayfly while a malfunctioning OBS-3 turbidity sensor was also connected to the Mayfly on another port. – Yes I have removed the turbidity sensor and still end up with -9992 values. 

    Thanks again for your help and I look forward to your replies.