Timeline for Confusion with grounding floating sources to be used with a differential ended data acquisition board
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 14, 2018 at 12:41 | vote | accept | floppy380 | ||
| Mar 13, 2018 at 11:25 | comment | added | Andy aka | I don't know what AIGND connects to - I would assume it connects through to "earth" at some point but this is down to you. Measuring it on a good day might convince you it will work but, on a bad day it could be several volts peak to peak. You need to estimate/calculate what it might be worst case. Again, I can't help you with this because I know nothing about your plant/factory/installation set-up. If CM voltage is high then you have to use isolation methods. Measuring with a meter doesn't tell you anything about any RF/high frequency CM noise unless you have a suitable meter. | |
| Mar 13, 2018 at 11:16 | comment | added | floppy380 | Thanks but I have some lack of knowledge when I look at these figures. 1-) For example in your drawing AIGND is not connected to earth ground right? 2-) Can I measure that common-mode voltage by a multimeter AC setting? 3-) If the commonmode voltage is high what can be the workaround for this config? | |
| Mar 13, 2018 at 11:12 | history | answered | Andy aka | CC BY-SA 3.0 |