Syntax 

The di_burst_rate function should not be called for these instruments (count is not used to determine the Burst Rate). The burst rate is always Baud Rate/20:

See Baud Rates to look up your instrument's possible Baud Rates.

Calculate the Burst Rate per Channel using the following formula:

Calculate the Burst Rate using the following formula:

Where: count is an integer that allows the burst rate to be modified. The integer range that determines burst rate is: 14,745,600/(BaudRate/32) <= count <= 65,535.

See Baud Rates to look up your instrument's possible Baud Rates.

Calculate burst rate using the following formula:

Where: count is an integer that allows the burst rate to be modified. The integer range that determines burst rate is: ceil(14,400/(BaudRate/20)) <= count <= 255. The ceil functions converts to an integer, rounding up if there is any fractional part.

See Baud Rates to look up your USB instrument's possible Baud Rates. Baud Rate is always 115,200 for Ethernet devices.

In most instances, the default value of 40,000Hz is sufficient. However the burst rate can be modified to accommodate a specific sampling rate. The equation that governs burst rate is:

Where: count is an integer that allows the burst rate to be modified. The integer range that determines burst rate is: 32 <= count <= 32,767 for DI-400 Series instruments or 64 <= count <= 32,767 for DI-500 Series, DI-720, DI-730, and DI-5001 instruments.

Note: DI-730 instruments should never use a burst rate above 150,000. DI-720 USB devices should not use acquisition methods other than “Last Point” if burst rate exceeds 150,000.

In most instances, the default value of 80,000Hz is sufficient. However the burst rate can be modified to accommodate a specific sampling rate. The equation that governs burst rate is as follows:

Rev A and B units:*

Rev C and higher units:*

*Revision levels are returned by the pal1_rev structure element in the di_info function.

Where: count is an even integer that allows the burst rate to be modified. The integer range that determines burst rate is: 200 <= count <= 32,767 (for Rev. A or B) or 300 <= count <= 43,690 (for Rev. C and higher). Note that count must be an even number. If an odd value is entered for count, it will automatically be converted to an even value, rounded down.

The equation that governs sample rate is:

Where: count is an integer that allows the sample rate to be modified. The integer range that determines sample rate is: 1 <= count <= 32,767.

Note: Burst Rate and Sample Rate are the same for the DI-700. When running under WindowsXP, scanned data will be corrupted unless count >=2.

Minimum Burst Count	Maximum Continuous Rates†		Simultaneous Data Acquisition tasks
	Standard Parallel Port	Bi-directional Parallel Port	ADC Input	DAC Output	Signal Averaging	Pre-/Post-Triggering
193	12.5kHz	25kHz	×
193	12.5kHz	25kHz		×
193	30kHz	37.5kHz	×		×
193	80kHz‡	80kHz‡	×			×
193	12.5kHz	25kHz	×	×
193	30kHz	37.5kHz	×	×	×
193	80kHz‡	80kHz‡	×		×	×
193	60kHz‡	60kHz‡	×	×		×
193	50kHz‡	50kHz‡	×	×	×	×
*based on a 33MHz ‘486. †All non-triggered modes indicate continuous throughput to disk. ‡All triggered modes indicate throughput to on-board 8kb FIFO memory only.

For example, with a DI-220, the fastest sampling rate you could program while simultaneously inputting data, outputting data, averaging data, and triggering is 50kHz.

Minimum Burst Count	Maximum Continuous Rates†	Simultaneous Data Acquisition tasks
		ADC Input1	ADC Input2	DAC Output**	Trig <= FIFO‡	Trig > FIFO‡
32	500kHz	×
64	250kHz		×
64	250kHz		×			×
64	250kHz		×		×
64	250kHz			×
128	125kHz		×	×
*based on a 75MHz Pentium. **The DI-401 is not capable of DAC output. †All non-triggered modes indicate continuous throughput to disk. All triggered modes indicate throughput to on board 15kb FIFO memory only. ‡Trig = (pre-trigger samples + post-trigger samples) × number of channels. FIFO = (7500 / number of channels) × number of channels. 1Without signal averaging or min/max calculations. 2With signal averaging and min/max calculations.

Minimum Burst Count	Maximum Continuous Rates†			Simultaneous Data Acquisition tasks
	Standard Parallel Port	Bi-directional Parallel Port	Enhanced Parallel Port	ADC Input	DAC Output	Trig <= FIFO‡	Trig> FIFO‡
64	30kHz	60kHz	180kHz	×
64	30kHz	60kHz	180kHz	×			×
64	250kHz	250kHz	250kHz	×		×
64	30kHz	60kHz	180kHz		×
64	15kHz	40kHz	125kHz	×	×
*based on a 75MHz Pentium. †All non-triggered modes indicate continuous throughput to disk. All triggered modes indicate throughput to on-board 8kb FIFO memory only. ‡Trig = (pre-trigger samples + post-trigger samples) × number of channels. FIFO = (7500 / number of channels) × number of channels.

Minimum Burst Count	Maximum Continuous Rates†		Simultaneous Data Acquisition tasks
	USB	ENB	ADC Input	Signal Averaging	Trig <= FIFO‡	Trig > FIFO‡
64	150kHz	150kHz	×
64	150kHz	150kHz	×			×
64	250kHz	250kHz	×		×
64	150kHz	150kHz	×	×
64	150kHz	150kHz	×	×		×
†All non-triggered modes indicate continuous throughput to disk. All triggered modes indicate throughput to on-board 8kb FIFO memory only. ‡Trig = (pre-trigger samples + post-trigger samples) × number of channels. FIFO = (7500 / number of channels) × number of channels.

Minimum Burst Count	Maximum Continuous Rates†		Simultaneous Data Acquisition tasks
	USB	ENB	ADC Input	Signal Averaging	Trig <= FIFO‡	Trig > FIFO‡
64	150kHz	150kHz	×
64	150kHz	150kHz	×			×
64	150kHz	150kHz	×		×
64	150kHz	150kHz		×
64	75kHz	75kHz	×	×
†All non-triggered modes indicate continuous throughput to disk. All triggered modes indicate throughput to on-board 8kb FIFO memory only. ‡Trig = (pre-trigger samples + post-trigger samples) × number of channels. FIFO = (7500 / number of channels) × number of channels.

Minimum Burst Count	Maximum Continuous Rates†		Simultaneous Data Acquisition tasks
	USB	ENB	ADC Input	Signal Averaging	Trig <= FIFO‡	Trig > FIFO‡
64	50kHz	50kHz	×
64	50kHz	50kHz	×			×
64	50kHz	50kHz	×		×
64	50kHz	50kHz		×
64	25kHz	25kHz	×	×
†All non-triggered modes indicate continuous throughput to disk. All triggered modes indicate throughput to on-board 8kb FIFO memory only. ‡Trig = (pre-trigger samples + post-trigger samples) × number of channels. FIFO = (7500 / number of channels) × number of channels.