Hi,

I do an evaluation on the 4227. I use picoscop6, 2 Channels, no Trigger,

dc coupling, autorange, samplerate 1.5626Ms/s, 50ms acquisition time,

78130 samples per channel. I save the data in an .txt file, three columns:

time, channel 1, channel 2.

My analog signal is a 1.5Vpp sine, 200Hz from a hp signal Generator. The

signal is applied to two voltage dividers, 100R by 100R. The output signal

of the two voltage dividers is fed into the two channels of the 4227.

I analyze the two signals with a matlab script. I do a fft and calculate

the phase shift between the two signals.

I exspect a constant value, close to zero.

I do get ( 7 measurements ):

-8.6792e-004 rad, -8.2561e-004 rad, -8.8991e-004 rad, -8.9823e-004 rad,

-8.4968e-004 rad, -1.0148e-003 rad, -8.7078e-004 rad

One of the results is more than 10^-4 rad off the mean value, standard

deviation is close to 6e-5 rad.

That is to much for the anticipated use.

Questions:

Do you see any flaws in the setup?

Faulty software setup?

How do I get a more constant phase delay between the channels?

The 4227 does a multiplexing, using one ADC for two channels?

Are there any other pico products with two ADCs for two channels and

constant phase delay between the channels?

Second observation:

The recorded sample timestamps from the file are not equally spaced,

though the 4227 uses uniform sampling ?! Could this be the problem?

thank you for reading

Cheers

Detlef