Chapter 4 Signal ConnectionsPCI-MIO E Series User Manual4-26 ©National Instruments CorporationAll digital timing connections are referenced to DGND. This referenceis demonstrated in Figure 4-10, which shows how to connect an externalTRIG1 source and an external CONVERT* source to two PCI-MIO ESeries board PFI pins.Figure 4-10. Timing I/O ConnectionsProgrammable Function Input ConnectionsThere are a total of 13 internal timing signals that you can externallycontrol from the PFI pins. The source for each of these signals issoftware-selectable from any of the PFIs when you want externalcontrol. This flexible routing scheme reduces the need to change thephysical wiring to the board I/O connector for different applicationsrequiring alternative wiring.You can individually enable each of the PFI pins to output a specificinternal timing signal. For example, if you need the CONVERT* signalas an output on the I/O connector, software can turn on the output driverfor the PFI2/CONVERT* pin. Be careful not to drive a PFI signalexternally when it is configured as an output.TRIG1SourceDGNDPFI0/TRIG1PFI2/CONVERT*CONVERT*SourceI/O ConnectorE Series Board
