What is a "current load" on a 24 V input used for?
Their reasoning:


  The C/Q and DI inputs have selectable current sinks that can be
  enabled for use in actuators where the master requires a Type 2 load.


What is a Type 2 load?

I'm not so sure on this one, but the hint I found was on the Pepperl and Fuchs page:


  Switching point   according to DIN EN 61131-2 (Type 2)
  
  0 (unattenuated)  ≤ 3 mA
  
  1 (attenuated)    ≥ 5 mA


I don't have access to the DIN EN 61131-2, so I cannot give a more detailed explanation. Seems like there is a digital input standard related to current and 7&nbsp;mA seems like a safe number to make something go high.