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controlling switched voltage power, weak signal to modem


ekahler Nov 19, 2015 10:14 PM

I have a couple of different issues:

I had my modem (LS300G) attached to the SW12 and G ports per the wiring diagram - initially it was working fine and I was able to send programs wirelessly from my PC to the datalogger and it compiled them fine. Then the power to those ports turned off and the modem shut down - I had to rewire it through the regular 12V and G ports on the datalogger to get it to power up again. However, I also had to use those ports to power up two sensors, and my signal on the modem became very weak and wouldn't not consistently work to connect to the datalogger. I tried to create, send, and compile a program using Shortcut to tell the CR800 to turn on the switched voltage at certain times, but because of the weak signal (I think) it was unable to compile the program, even though it said it was sent successfully. I was able to compile (though not send) the same program in CRBasic Editor.

I now have the modem plugged into the switched voltage again, but it has not powered on in the last 1.5 hours (the program was to power it up every 30 minutes). I even tried hooking it up to the regular 12V ports again and disconnecting all the sensors - my signal strength went up but the datalogger was still unable to compile the program.

Any ideas why the switched voltage ports would have autonomously cut off power to the modem, and why I can't get them to turn back on again? Also is there possibly some other reason than signal strength why the CR800 would stop being able to receive and compile a program? I did try deleting old files through the Connect program in Loggernet but it didn't help.

For the record, ALL of these problems except the dead switched voltage ports on the datalogger began after I switched the modem set up from serial to PPP.

* Last updated by: ekahler on 11/19/2015 @ 3:55 PM *


JDavis Nov 20, 2015 12:00 AM

It is expected that you will lose your connection to the datalogger while it recompiles the program. The PPP connection to the modem can take a couple minutes to establish once the modem powers up.

Check the compile results in the Status table of the datalogger. You could be running an older OS version on the datalogger which doesn't support some instructions you added to your program.

The current version of ShortCut has a Switched 12 Volt Timed Control in the Control group. I recommend using the code that generates for modem power control.


pokeeffe Nov 20, 2015 08:28 PM

The nominal rating of the LS300G is 1000 mA, which exceeds the stated maximum supply current for SW12V ports. You're witnessing correct operation of the thermal fuse.

Take a look at section 5.4.3 Component Built Relays (CR3000 User Manual, rev 7/11). I don't know what the section reference is for the current user manual version.

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