PXI (Sheet 10): AC termination and pull-up on PXI_TRIG
According to PXI Express Hardware Specification section 4.3.2 Trigger Bus: "PXI_TRIG[0:7]
SHALL
be AC terminated with a 50 Ω resistor and 33 pf cap at both ends of the bus segment in addition to
the diode termination required in the PXI-1 specification"
In the same section there is a requirement on pull-up for these trigger signals