© National Instruments | 1-37NI cDAQ-9138/9139 User Manual– The Digital Input Triggering Signals section of Chapter 4, Digital Input/Outputand PFI– The Digital Output Triggering Signals section of Chapter 4, Digital Input/Outputand PFI• Independent Data Streams—The cDAQ controller supports seven independenthigh-speed data streams, which allow for up to seven simultaneous hardware-timed tasks,such as analog input, analog output, buffered counter/timers, and hardware-timed digitalinput/output.• PFI Signals—The PFI signals provide access to advanced features such as triggering,synchronization, and counter/timers. You can also enable a programmable debouncingfilter on each PFI signal that, when enabled, samples the input on each rising edge of a filterclock. PFI signals are available through parallel digital input and output modules installedin up to two controller slots. Refer to the PFI section of Chapter 4, Digital Input/Outputand PFI, for more information.• Flexible Counter/Timers—The cDAQ controller includes four general-purpose 32-bitcounter/timers that can be used to count edges, measure pulse-widths, measure periods andfrequencies, and perform position measurements (encoding). In addition, thecounter/timers can generate pulses, pulse trains, and square waves with adjustablefrequencies. You can access the counter inputs and outputs using parallel digital I/Omodules installed in up to two slots. Refer to Chapter 5, Counters, for more information.Processor and PortsRefer to the specifications document for your cDAQ controller for information about theprocessors on the cDAQ controller. Refer to the cDAQ Controller Features section forinformation about using the various ports on the cDAQ controller.
