Does the 6239 slew rate varry?

[Schliepe]

I am using two PXI-6239 Multifunction DAQ cards to create a biphasic output current wave.  For one application where I need the current outputs to be 20mA and 1mA it works just fine.  When I try and use the same exact code but at much lower current output, like 80uA, I'm getting rise times much slower than the expected .8uS.  The specifications state a .1mA/uS slew rate and I'm wondering if there are any restrictions to that or if there is some nuance that I'm overlooking.  Any help would be appreciated.  Thank you,

Erich

[Jason_D]

Erich,

How are you measuring this slew rate/amperage?  If you just measure across a resistor do you get the same results?  Please make sure the circuit you are attaching to doesn't have inductive or capacative elements.

[Schliepe]

I was measuring the voltage through a PXI-5922 Scope card and across a resistor.