On page 3 of the PCIe 6341 spec sheet, in the section "Analogue Output". it states that the maximum current drive for the device is 15mA (but it shouldn't really be asked for more than 5mA).

Given what's on the scope screen, it seems like you aren't asking for that amount of current (from your first image):

$$ I = \frac{V}{R} = \frac{2V}{470\Omega} = 4.3mA $$

In the bottom image, though, I see that clipping happens at 1V peak, so I'm wondering if you haven't got your probe set to x10, and the real voltage being output is rather 10V:

$$ I = \frac{10V}{470\Omega} = 21mA $$

It's above the stated 15mA maximum, but it's close, and I imagine that NI's specifications are somewhat conservative.

On page 3 of the PCIe 6341 spec sheet, in the section "Analogue Output". it states that the maximum current drive for the device is 15mA (but it shouldn't really be asked for more than 5mA).

Given what's on the scope screen, it seems like you aren't asking for that amount of current (from your first image):

$$ I = \frac{V}{R} = \frac{2V}{470\Omega} = 4.3mA $$

In the bottom image, though, I see that clipping happens at 1V peak, so I'm wondering if you haven't got your probe set to x10, and in reality the signal is being clipped at 10V:

$$ I = \frac{10V}{470\Omega} = 21mA $$

It's above the stated 15mA maximum, but it's close, and I imagine that NI's specifications are somewhat conservative.