National Instruments NI DIDS-2103 User Manual page 78

Channel Output Illustration
78 | ni.com | NI DIDS-2100 Series User Manual
ACTIVE HIGH DIG OUT: This mode allows for driving a device accepting an active high
digital input engine synchronously. The corresponding channel remains on and sinks current
through the pullup resistor throughout most of the engine cycle. The channel turns off and
stops sinking current as specified by an engine synchronous event or an external input. At
the end of the event, the channel turns back on and begins sinking current again, as in the
Channel 2 Illustration above. You must wire a pullup resistor between terminal 0 and the
corresponding PFI channel in order for the output to function properly.
IF USERS SET THE PFI CHANNEL OUTPUT MODE to ACTIVE HIGH DIG OUT WHEN
CONNECTED TO A FUEL INJECTOR, THE POLARITY OF THE INJECTION EVENT
WILL CHANGE AND THE INJECTOR WILL INJECT FUEL DURING THE MAJORITY OF
THE ENGINE CYCLE. BE CERTAIN TO SET THE MODE TO NORMAL TO DRIVE A PFI
INJECTOR.
Tip Strip: Illustrates the current and voltage profiles for the corresponding PFI channel give
its selected mode.
Details: The plot shows an example current and voltage profile for the selected mode
assuming that the mode is wired properly. For all three modes, the current plot shows
the amount of current flowing into the PFI channel. In NORMAL mode, the plot illustrates
the differential voltage that would be measured across the injector. In ACTIVE HIGH DIG
OUTPUT and ACTIVE LOW DIG OUTPUT, the plot shows the voltage measured at the
corresponding PFI channel pin.
The check boxes next to the key next to the current and voltage plots allow users to enable
and disable the corresponding current and voltage plots to more clearly see one plot or the
other.