What are the Terminology Changes in NI-DAQmx? - National Instruments

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What are the Terminology Changes in NI-DAQmx?

Hardware: Multifunction DAQ (MIO)

Problem: What are the Terminology Changes in NI-DAQmx?

Solution: NI-DAQmx defines common terms for common concepts and uses the same terminology across all ADEs. Specifically, the LabVIEW API, C API, and DAQ Assistant all employ the same terminology. Additionally, DAQ device pin descriptions have been updated to reflect the NI-DAQmx terminology.

The following information is found in the NI-DAQmx Help under the topic Traditional NI-DAQ Versus NI-DAQmx. The NI-DAQmx Help is found by following the path Start»Programs»National Instruments»NI-DAQ.

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Input Clock and Trigger Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Sample Interval Counter (and Channel Clock)	Channel Clock or Interchannel Delay	AI Convert Clock	The E Series clock that directly causes analog-to-digital conversions
Points per Second (as Sample Rate)	Channels per Second	Conversions per Second	Units for specifying AI convert clock rate
Sample Timebase (and Channel Clock Timebase)	Timebase	AI Convert Clock Timebase	The clock that is divided down to produce the AI convert clock
Sample Interval	Timebase Divisor	AI Convert Clock Timebase Divisor	The number of AI convert timebase ticks used to divide down the AI convert timebase
Scan Interval Counter (and Scan Clock)	Scan Clock	Sample Clock	The clock that controls the time interval between samples. Each time the sample clock ticks (produces a pulse) one sample per channel is acquired.
Scans per Second (as scanRate)	Scans per Second	Samples per Channel per Second	Units for specifying sample acquisition rate (the sample rate)
Scan Timebase	Timebase	Sample Clock Timebase	The clock that is divided down to produce the sample clock
Scan Interval	Timebase Divisor	Sample Clock Timebase Divisor	The number of sample clock timebase ticks used to divide down the sample clock timebase
Start Trigger	Start Trigger	Start Trigger	The trigger that begins an acquisition
Stop Trigger	Stop Trigger	Reference Trigger	The trigger that creates the reference point between the pretrigger samples and the post-trigger samples
No Equivalent	Scan Clock Gating	Pause Trigger	The signal that pauses and resumes an acqusition
No Equivalent	ATCOUT	Analog Comparison Event	The signal from the analog comparator circuit, used most often for analog triggering
SCANCLK	SCANCLK	AI Hold Complete Event	A digital signal emitted by an E Series device when the analog signal about to be converted by the ADC has been held

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Input Read Terminology in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Reading, Voltage, Sample	Sample	Sample	A single measurement from a single channel
Scan	Scan	No Equivalent	A set of samples, one from each channel in the task
Sample Count	Scans per buffer	Buffer Size (in Samples Per Channel)	Method for specifying the buffer size
No Equivalent — the Sequential parameter in `DAQ_Monitor` is the closest	Read/Search Mode	Position	Where to place the read position prior to adding the offset
No Equivalent	Read/Search Offset	Offset	After placing the read position, this offset is added to determine where the read takes place; all subsequent reads use this offset until the offset is changed
No Equivalent	Read Mark Scan	Current Sample Number	The current read position
No Equivalent	Scan Backlog	Available Samples Per Channel	The amount of unread data in the buffer
Retrieved	End of Data Scan	Total Samples Per Channel Acquired	The total number of samples acquired into the buffer
Count	Total Scans to Acquire	Samples per Channel	The total number of samples to acquire
numPts	Number to Read	Number of Samples per channel	The number of samples to read

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Input Physical Channel Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ	NI-DAQmx	Explanation
0,1, and so on	Dev1/ai0, Dev1/ai1, and so on	In Traditional NI-DAQ, physical channel names were numbers. In NI-DAQmx, physical channels are string names that combine the device name, the I/O type, and the physical channel number

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Output Clock and Trigger Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Update Clock	Update Clock	Sample Clock	The clock that causes D/A conversions
Updates per Second	Updates per Second	Samples per Channel per Second	Units for Specifying digital-to-analog conversion (DAC) rate
Timebase	Timebase	Sample Clock Timebase	The clock that is divided down to product the sample clock
Interval	Timebase Divisor	Sample Clock Timebase Divisor	The number of sample clock timebase ticks used to divide down the sample clock timebase
Start Trigger	Start Trigger	Start Trigger	The trigger that begins a generation
No Equivalent	Gate	Pause Trigger	The signal that pauses and resumes a generation

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Output Write Terminology in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Voltage, Sample	Update	Sample	A single measurement generated at a single channel
No Equivalent	Update	No Equivalent	A set of samples, one for each channel in the task
No Equivalent	Write Mode	Position	Where to place the write position prior to adding the offset
No Equivalent	Write Offset	Offset	After placing the write position, this offset is added to determine where the write will take place. All subsequent writes will use this offset until the offset is changed
No Equivalent	Write Mark	Current Sample Number	The place in the buffer where the next write begins if the Position property/attribute is Relative to Current Write Position and the Offset property/attribute is 0
No Equivalent	No Equivalent	Space Available in Buffer	The number of samples that can be written without overwriting a sample that has not been output
pointsDone, itersDone	Output Mark, Buffer Iterations	Total Samples Per Channel Generated	The total number of samples that have been written to the device; although the samples have been written to the device, they may not have been generated yet
oldDataStop	Regeneration Mode	Regeneration	The property/attribute that controls whether old data is regenerated
partialTransfer	Regeneration Mode	No Equivalent	To stop a waveform generation after a specific number of samples are generated, set the NI-DAQmx property/attribute samples per channel to the desired number of samples
Iterations	Iterations	Samples per Channel	To generate a finite number of iterations of a buffer, set the samples per channel property/attribute to I × N, where I is the desired number of iterations, and N is the number of samples per channel in the buffer.

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Analog Output Physical Channel Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ	NI-DAQmx	Explanation
0,1, and so on	Dev1/ao0, Dev1/ao1, and so on	In Traditional NI-DAQ, physical channel names were numbers. In NI-DAQmx, physical channels are string names that combine the device name, the I/O type, and the physical channel number

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Counter Clock and Trigger Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Start Trigger	Start Trigger	Start Trigger	The signal that begins a counter operation
Gate	Gate	Pause Trigger	The signal that pauses and resumes a counter operation

The following table translates terms from Traditional NI-DAQ to NI-DAQmx.

Counter Application Names
Traditional NI-DAQ C API	Traditional NI-DAQ LabVIEW	NI-DAQmx	Explanation
Event Counting	Event Counting	Edge Counting	A counter tallies the total number of rising or falling edges
No Equivalent	Frequency Shift Keying	NI-DAQmx does not support Frequency Shift Keying

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Counter Physical Channel Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ	NI-DAQmx	Explanation
0, 1, and so on	Dev1/ctr0, Dev1/ctr1, and so on	In Traditional NI-DAQ, physical channel names were numbers. In NI-DAQmx, physical channels are string names that combine the device name, the I/O type, and the physical channel number

The following table translates terms from Traditional NI-DAQ to NI-DAQmx for both the C API and LabVIEW API.

Digital Physical Channel Names in Traditional NI-DAQ and NI-DAQmx
Traditional NI-DAQ	NI-DAQmx	Explanation
0, 1, as port	Dev1/port0, Dev1/port1, and so on	In Traditional NI-DAQ, physical channel names were numbers. In NI-DAQmx, physical channels are string names that combine the device name, the I/O type, and the physical channel number. If the line number is omitted from the NI-DAQmx name, all lines in the port are included.
0, 1 as line	Dev1/port0/line0, Dev1/port0/line1	When the line number is present in the NI-DAQmx name, only that line is meant
No Equivalent	Dev1/port1_16	Concatenated ports, porta_b, where a is the port number of the beginning port and b is the width in lines

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Report Date: 05/08/2003
Last Updated: 06/12/2007
Document ID: 2X7MTTN1

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