Hello all, I am trying to wire six D6 dendrometer (Meter group), which has a strain-gage full-bridge sensor (which requires an excitation of at least 5V) connected to a TensioLINK multiplexer, which is SDI-12. I would like to wire the SDI-12 sensors in AM16/32B multiplexer connected to a CR300 datalogger. I know I could use all the SDI-12 sensors directly to C1, G and 12 V in the CR300 datalogger but I would like to have the sensors separated and avoid using a bus to connect them to one port.
I was planning to connect the sensors like that:
4 wired cable:
C1 (datalogger) - CLCK (multiplexer)
C2 (datalogger) - RES (multiplexer)
SW12 (datalogger) - 12 V (multiplexer)
G (datalogger) - G (multiplexer)
4 wired cable:
1 H (datalogger) - COM EVEN H (multiplexer)
1L (datalogger) - COM EVEN L (multiplexer)
Vx1 (datalogger) - COM ODD L(multiplexer)
G (datalogger) - COM ODD L (multiplexer)
I tested connecting to this way and the multiplexer is working with the CR300 but I do not know how to wire the sensors SDI-12 to the multiplexer. Is that possible? I tried to use the short-cut to create a program using the CR300 but it does not give me an option to have the AM16/32B as well.
Please, any help??
Also, does anyone have used this type of dendrometer?
Thank you so much!
Jessica,
I think the simplest solution for you would be to change the addresses in the sensors to 1 thru 6 and use the SDI capabilites of the CR300.Connect them to the datalogger one at a time and use the terminal emulator and SDI commands to change the addresses.
https://www.campbellsci.com/videos/sdi12-sensors-transparent-mode
You could put three in C1 and three in C2 if that helps. They are serial sensors and therefore cannot be read by the analog inputs of the logger.
Dave
Hi Dave
Thank you so much for your reply! Things are clear now.
Jessica
As you are now getting assistance from others in the forum, I'll bow out of the conversation.
Dave
Hi Dave, sure. I appreciate your assistance! thank you!
Hello Jessica & Dave,
I just purchased a mutliplex, CR310, and a couple SDI-12 Devices per the reccomenadation of the sales group. It is now my undersatnding that the Short Cut Software does not have a connection for the CR310 and AM16/32. I called support and they said i could add some additonal code to make this work.
My question to you both would be do you have any of this code? Or how it can be completed? Aany help would be greatly appreciated.
Thanks,
Greg
Hi Greg
I do not have the code and I do not really know how to make the multiplexer work with SDI-12 sensors. I tried several ways and I just gave up on using the multiplexer for my case. From my understanding, the multiplexer was designed to multiplex analog sensors, not serial sensors (like SDI-12), but I am not an expert on it. If Campbell said it is possible, so it is =)
I will tell you what I did to make my sensors work:
Ps. I followed Dave suggestion (Thanks Dave for that)!
I gave every SDI-12 sensors a different address (from 0 to 9), and I connected them to SDI-12 ports (C1 and C2) on the datalogger (CR300 my case). To do it I used some terminal strips (I had to do it because I have many SDI-12 sensors).
For the program, I used the examples that meter group provide. https://www.metergroup.com/environment/articles/sdi-12-example-programs/
I played a bit with the program until I understand the output, and then I created the program for my case.
Again, I am not an expert but I am glad to help you if you have any other question.
Jessica