Hello again, hoping this is the last time I have to bother you. I am trying to read a pH sensor and it reads fine when it is the only sensor being measured. I can have a LJTick or other signal connected but as soon as I try to read both the pH read goes to full range negative. I have settling time maxxed out at 50000 for the pH channel. Wondering if it needs more? Maybe I need a lJTick-InAmp or a resistor/capacitor somewhere.
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The LJTick-InBuff is usually needed for pH sensors:
https://labjack.com/support/datasheets/accessories/ljtick-inbuff
... but it is interesting that you get good readings when the pH channel is the only channel you are acquiring. That suggests that some amount of settling might be enough, but 50 ms is not enough. If you want to investigate further and can write your own software you can do testing using a simple program that does the following:
Connections:
AIN0 - pH
AIN1 - GND
AIN2 - VS
Pseudocode:
Junk = Read AIN1
Junk = Read AIN0
Delay
Value1 = Read AIN0
Junk = Read AIN2
Junk = Read AIN0
Delay
Value2 = Read AIN0
See how much delay (this is a software delay you adjust) is required until Value1=Value2 and is the correct value.