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OpNI671x Frequency In




The National InstrumentsNI671x cards feature analog inputs, analog outputs, digital I/O lines and counters. This block is used to control one of the two counters to perform frequency measurement on digital signals.

This block supports a list of PXI and PCI cards. For more card-specific information, please refer to NI documentation.


Bus TypeSee the glossary definition.
Board TypeSelect the card model (6713 or 6711) on this list.
Card index (PCI/PXI index)See the glossary definition.
CounterEach board has two counters. Select the counter to be used (0 or 1)
Clock sourceSets the counting clock of the counter to either20MHz or 100kHz. Clock selection has a direct impact on resolution.
GateInput to be used for the counter.

See the glossary definition.


This block has no inputs.


FreqAt each calculation step, this outport returns the last frequency measurement performed by the NI671x counter.

Characteristics and Limitations

Connector Pin Assignments

The following table gives the description of the signals related to the digital input channels and is followed by the connector pin assignments of the NI671x 68-pinI/O connector.

68-pin I/O

Pin Description Pin Description 
34AnalogOut Ground68Not Connected
33Not Connected67AnalogOut Ground
32AnalogOut Ground66AnalogOut Ground
31AnalogOut Ground65DAC7OUT
30DAC6OUT 64AnalogOut Ground
29AnalogOut Ground63AnalogOut Ground
28DAC5OUT 62Not Connected 
27AnalogOut Ground61AnalogOut Ground
26AnalogOut Ground60DAC4OUT 
25DAC3OUT 59AnalogOut Ground
24AnalogOut Ground58AnalogOut Ground
23AnalogOut Ground57DAC2OUT 
22DAC0OUT 56AnalogOut Ground
21DAC1OUT 55AnalogOut Ground 
20EXTREF 54AnalogOut Ground 
19Digital IO 453Digital Ground
18Digital Ground52Digital IO 0
17Digital IO 151Digital IO5
16Digital IO 650Digital Ground
15Digital Ground49Digital IO 2
14+5V48Digital IO 7
13Digital Ground47Digital IO 3
12Digital Ground46Not Connected
10PFI144Digital Ground
9Digital Ground43PFI2
7Digital Ground41PFI4/GPCTR1_GATE
5PFI6/WFTRIG39Digital Ground
4Digital Ground38PFI7
2GPCTR0_OUT36Digital Ground
1FREQ_OUT35Digital Ground
Direct FeedthroughNo
Discrete sample timeNo
XHP supportYes
Work offlineNo

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