Incomprehensible interference and baseline offset in Y.

[Oknehsomit]

Hello, I started to understand the equipment of PXIe-1092, PXIe-6396, PXIe-8880, TB-2706. I wrote a small program in Labview to register the signal from the detector. And when power is applied to the detector, the baseline shift along Y occurs, up to 5 volts (pic 2). I don't understand why this is happening. After that, a signal with an amplitude of 10-100 mV is observed, but the base line along Y is still shifted (from -5 Volts to -3 Volts). When the Y offset reached ~ 3 Volts (pic 3), incomprehensible interference with an amplitude of 3-5 volts began (pic 4). After that, you have to wait for some time so that the signal can be observed again from this channel. I do not understand what the problem is, since this is not the specifics of my work, but no one at work can tell me the cause of the problem. Help please. 

In general terms, this program should work like an oscilloscope, since you have to compare the signal with a conventional oscilloscope. By the way, on the oscilloscope this signal is not shifted in Y and there are no problems in amplitude.

Pic 1

Pic 2 Signal pulsesPic 3 ~ 3 Volts, when incomprehensible interference begins.

Pic 4

[VA.KI]

Hello,

First of all, would be helpful to know how the wiring is done or what is the signal source is?

What terminals of PXIe-6396 you have connected to the external device?