Figure 4 of the NI USB-6501 OEM User Guide shows a port IO circuit. Rp is populated with a 4.7 kOhm pull up resistor. The documentation states an output can be configured as push-pull. Does that indicate that actual micropin on the USB microcontroller, as shown in Figure 3 block diagram, will be configured as push-pull, basically overriding the pull up / open drain circuit? Is there circuit diagram of what an actual port pad looks like? That is, when push-pull, does the port pad have a dual transistor circuit connected to it?
Reviewing the PCB, I observe a low side transistor on all the pins with the 4.7 kOhm pull up resistor, Rp.
Thank you.