Hello everyone,
I tried to record on 4 channels with the 8ch Analog Input Module and noticed that the last 2 channels, mostly independent of the number of active channels, show a repeating artificial signal.
When I try to use more than 2 channels, I see following events on the scope:
2 channels: everything looks fine
4 channels: channel 3&4 show a repeating, increasing trace, which falls back to -10V after reaching an unknown maximum
6 channels: channel 5&6 show the same trace, but I also tried setting the active channels to 7 mid-trace, which resulted in a shift of channels 5&6
Also, channel 6 returned to a flat trace, which is to be expected, since only channels 1-4 are connected.
8 channels: everything looks fine again
The fact that I can influence the traces by selecting the active channels, without changing anything about the sampling rate, suggests in my opinion, that this is a software issue.
Do you know what could cause this? Or how to solve this issue?
On another note: I looked into the Analog Input Module code at https://github.com/sanworks/Bpod_Gen2/blob/master/Functions/Modules/Analog%20Input/BpodAnalogIn.m and noticed that the valid sampling rates are set with [b]ValidSamplingRates = [1 10000]; % Range of valid sampling rates, which suggests that only rates up to 10kHz are allowed, but all documentation I could find mention 100kHz as the upper limit.
Is this a mistake and this line should read [b]ValidSamplingRates = [1 100000]; % Range of valid sampling rates?
EDIT: So, apparently I am not allowed to upload any attachments. I hope everyone can still imagine what I mean with my descriptions.
Cheers,
Marti
