jcallen1 Posted January 8, 2014 Share Posted January 8, 2014 I am using LabJack u3 with DaqFactory Express and thanks to you guys help I finally have a program that logs and graphs varying voltage in 12 hour increments. However, the graphs and I suppose logging parameters tops out at 2.5 volts and does not graph input up to 5 volts which is the upper level of the equipment that I am monitoring. What changes do I need to make to the program to accommodate a 5 volt maximum level? Thanks James Link to comment Share on other sites More sharing options...
AzeoTech Posted January 8, 2014 Share Posted January 8, 2014 This is a hardware issue, so I'll let the LabJack guys respond. You'll probably need a voltage divider. Link to comment Share on other sites More sharing options...
LabJackSupport Posted January 8, 2014 Share Posted January 8, 2014 Do you have a U3-LV or U3-HV? If you have an HV, use one of the high-voltage channels AIN0-AIN3: http://labjack.com/support/u3/users-guide/2.6 If you only have low-voltage channels, you can build a voltage divider or buy an LJTick-Divider: http://labjack.com/support/u3/users-guide/2.6.3.6 Link to comment Share on other sites More sharing options...
SteveMyres Posted January 8, 2014 Share Posted January 8, 2014 Exactly. Wire two resistors of equal value in series, say in the 500 ohm to 2K range (Minimum value will depend upon the current sourcing capability of the equipment that's sending the signal). Apply your 5V across the network of two resistors, and take your voltage input from the point between the two resistors. Then 0-2.5V at the input means 0-5V at the equipment. You can also get signal conditioners with or without electrical isolation to scale signals, even changing from one type (current, resistance, low level voltage such as milivolts, RTD, thermocouple, thermistor, etc.) to a current or voltage that can be connected to your reading device (general comment, I'm not familiar with LabJack input capabilities in detail). Link to comment Share on other sites More sharing options...
jcallen1 Posted January 9, 2014 Author Share Posted January 9, 2014 I contacted the LabJack staff and they said setting the maximum voltage to 3.6 volt dc has to be accomplished through the software. Any ideas as how I would set this in the DaqFactory Express software? James Link to comment Share on other sites More sharing options...
jcallen1 Posted January 9, 2014 Author Share Posted January 9, 2014 Please disregard my previous post. I was just contacted again by the LabJack support representative who provided an explanation how to accomplish establishing the maximum voltage to 3.6 volts dc. Thanks James Link to comment Share on other sites More sharing options...
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