I have received ADALM2000 and tested it. Pin connections are as follows.
1+ —— W1
1- —— Gnd
I open the Scopy software and run the Oscilloscope without run the Signal Generator. The result is bellow.
A DC offset voltage about 160mV is acquired. I also use a multimeter to confirm the voltage between W1 and Gnd, the result is consistent.
When the Signal Generator and ch 1 is set to 0mV, the voltage acquired by the Oscilloscope is about 0.
I want to know whether this phenomenon is normal？ How to eliminate the DC offset voltage when the Signal Generator is not run？
I think the function generator output is in a high impedance state when off ( not running ) so you are seeing the internal input bias (leakage) current flowing in the 1 Mohm input resistor divider. Try grounding both 1+ and 1- (2+ , 2-) to observe the actual DC offset ( at 0 V input).
The generator must be running. If you need it to be at some specific DC level when not making a signal (i.e. sine waves) set to DC and required voltage (0V?).
There is a small voltage leaking to the output when the AWG is off - through the feedback resistor of the AD8000.
The current is only ~80uA so by loading the AWG this voltage will drop (1K -> ~50mV).