Chapter 4 Analog InputNI 6232/6233 User Manual 4-28 ni.comai/ConvertClockTimebase is not available as an output on the I/Oconnector.AI Hold Complete Event SignalThe AI Hold Complete Event (ai/HoldCompleteEvent) signal generates apulse after each A/D conversion begins. You can routeai/HoldCompleteEvent out to any output PFI <6..9> or RTSI <0..7>terminal.The polarity of ai/HoldCompleteEvent is software-selectable, but istypically configured so that a low-to-high leading edge can clock externalAI multiplexers indicating when the input signal has been sampled and canbe removed.AI Start Trigger SignalUse the AI Start Trigger (ai/StartTrigger) signal to begin a measurementacquisition. A measurement acquisition consists of one or more samples. Ifyou do not use triggers, begin a measurement with a software command.When the acquisition begins, configure the acquisition to stop under thefollowing conditions:• When a certain number of points are sampled (in finite mode)• After a hardware reference trigger (in finite mode)• With a software command (in continuous mode)An acquisition that uses a start trigger (but not a reference trigger) issometimes referred to as a posttriggered acquisition.Using a Digital SourceTo use ai/StartTrigger with a digital source, specify a source and an edge.The source can be any of the following signals:• Input PFI <0..5>• RTSI <0..7>• Counter n Internal Output• PXI_STARThe source also can be one of several other internal signals on your DAQdevice. Refer to Device Routing in MAX in the NI-DAQmx Help or theLabVIEW 8.x Help for more information.
