NI cDAQ-9178 - Module PFI Characteristics; Chassis PFI Characteristics (ni Cdaq-9178 Only); External Digital Triggers

© National Instruments Corporation 69 NI cDAQ-9178/9174 User Guide and Specifications
Module PFI Characteristics
Functionality ..........................................................Static digital input, static digital output, timing input,
and timing output
Timing output sources............................................Many analog input, analog output, counter,
digital input, and digital output timing signals
Timing input frequency..........................................0 to 20 MHz
Timing output frequency........................................0 to 20 MHz
Chassis PFI Characteristics (NI cDAQ-9178 Only)
Max input or output frequency ..............................1 MHz
Maximum voltage ..................................................25 V
Minimum voltage...................................................–20 V
Cable length ...........................................................3 m (10 ft.)
Cable impedance....................................................50 Ω
Connector...............................................................BNC
Output voltage
High ...............................................................5.25 V max
Sourcing 100 µA ....................................4.65 V min
Sourcing 2 mA .......................................3.60 V min
Low
Sinking 100 µA ......................................0.10 V max
Sinking 2 mA .........................................0.64 V max
Power-on state........................................................High impedance
External Digital Triggers
Source ....................................................................Any PFI terminal or chassis PFI terminal
(NI cDAQ-9178 only)
Polarity...................................................................Software-selectable for most signals
Analog input function ............................................Start Trigger, Reference Trigger, Pause Trigger,
Sample Clock, Sample Clock Timebase
Analog output function ..........................................Start Trigger, Pause Trigger, Sample Clock,
Sample Clock Timebase
Counter/timer functions .........................................Gate, Source, HW_Arm, Aux, A, B, Z, Up_Down
Minimum Maximum
Positive Going Threshold Voltage 1.43 2.28
Negative Going Threshold Voltage 0.86 1.53
Hysteresis 0.48 0.87