USB-1608G -10V on all channels

[Valid]

Hi,

I have some issues with a USB-1608G Multifunction DAQ Device, when in single-ended mode, nothing plugged in, all 16 channels report -10V. when I plug a source on one of the 16th channels it gives the right value, but the remaining 15 channels gives various voltages even if they are not plugged. I updated the firmware, I also tied to configure jumper W1 for either pull-up or pull-down, but It didn’t help.

Thanks

[JRys]

What you described is a normal operation. The USB-1608G is designed to work with low-impedance (<100 ohms) sources. Open or unconnected channels are high impedance. This causes the inputs to charge to some unknown voltage (-10v sounds right). Connect the other 15 channels to AGND to simulate a low-impedance source. If you do this, you will not see an image of the 16th channel on them.

Best regards,
John