I am using said link:
In a current application, R1 is 470K and R2 is 270K, I should also mention that I am using the LJ ControlPanel(LJCP) 2.32.
When I inject 1V, I should see ~0.335V on AIN3 which I do with a DMM, but in the LJCP I am getting voltages that fluctuate from -10V to 10V.
The flashing GRN LED to solid happens as should in normal operation.
I am able to drive other commands out of AIN1 and AIN2. Is this type of behavior associated with a bad Port on AIN3?
Thank you,
Lee
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One problem is that you are far exceeding the 1k source impedance limit of the high-voltage inputs:
https://labjack.com/support/datasheets/u3/appendix-a
Let us know the signal range you want to measure and we can provide some suggestions.
I missed that datasheet, my bad. I have my resistors on order for replacing previous values.
Thank you for the support.
There are other considerations also. What is the voltage range you want to measure?
The range is between 12-24V.
Note that Section 2.6.3.6 is talking about low voltage analog inputs (FIO & EIO). When you are using a voltage divider you want to put it in front of the low-voltage inputs, not the high-voltage inputs. Set up an R1:R2 ratio that brings your max voltage down to <2.4 volts. With normal measurements on the low voltage analog inputs you can use resistors up to 10k, and if you enable LongSettling you can use resistors up to 200k.
Another option is to buy one of our new LJTick-Dividers. We now have 4 options: -5, -10, -25, and -C, which correspond to divide by 5, divide by 10, divide by 25, and custom. These are not mentioned on our site yet, but we do have them. Divide by 10 would bring 24V down to 2.4V, which does not give you any room if the voltage goes much over 24V, so you would probably want the -25 option.