HP NuDAQ I-9111DG/HR manual Fifo Half-Full Polling

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It is possible to read A/D converted data without polling. The A/D conversion time will not exceed 8.5μs on PCI-9111 card. Hence, after software trigger, the software can wait for a t least 8.5 μs then read the A/D register without polling.

The data polling transferring is very suitable for the application need to process AD data in real time. Especially when combining with the timer interrupt generation, the timer interrupt service routine can use the data polling method to get multi -channel A/D data in real time and under fixed data sampling rate.

FIFO Half-Full Polling

The FIFO half-full polling mode is the most powerful AD data transfer mode. The 1 K words FIFO can store up to 10.24 ms analog data under 100 KHz sampling rate (10.024ms = 1024/100 KHz). Theoretically, the software can poll the FIFO every 10 ms without taking care how to trigger A/D or transfer A/D data.

ADLINK recommend user to check your system to find out the user software‘s priority in the special application. If the application software is at the highest priority, to poll the FIFO every 10 ms is suitable. However, the user‘s program must check the FIFO is full or empty every time reading data.

To avoid this problem, the half-full polling method is used. If the A/D trigger rate is 100KHz, the FIFO will be half-full (512 words) in 5.12 ms. If the user‘s software checks the FIFO half full signal every 5 ms. When the FIFO is not half-full, the software does not read data, because it is difficult to know how much A/D data is stored in the FIFO and user must check the FIFO empty bit every time reading data. When the FIFO is full, the AD FIFO is overrun. This means the sampling rate is higher than users expect or the polling rate is too slow, it is also possible due to your system occupy the CPU resource thus reducing the polling rate. When the FIFO is half-full and not full, the software can read one “block” (512 words) A/D data without check the FIFO status. This method is very convenient to read A/D in size of a “block” and it is benefit to software programming.

Usually, the timer trigger is used under this mode, therefore the sampling rate is fixed. The method also utilizes the minimum CPU resources because it is not necessary to be highest priority. The other benefit is this method will not use hardware interrupt resource. Therefore, the interrupt is reserved for system clock or emergency external interrupt request. The FIFO half-full polling method is the most powerful A/D data transfer mode.

Operation Theorem ∙27

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Contents NuDAQ Trademarks Questions Getting service from AdlinkPage B l e o f C o n t e n t s Features Applications Specifications Software SupportingPCI PnP Registers Address Map Hardware Interrupt Clear Register Libraries Installation Programming GuideConversion Interrupt ControlTable of Contents ∙ 9111util What do you need VR Assignment AdjustmentHow to Use This Guide Page Introduction FeaturesApplications SpecificationsUnipolar 0~10V Bipolar -10V~+10V Programming Library Software SupportingPCIS-VEE HP-VEE Driver PCIS-LVIEW LabVIEW DriverDAQBenchTM ActiveX Controls DASYLabTM PROPCIS-OPC OPC Server PCIS-ICL InControlTM Driver∙ Software Installation Guide InstallationWhat You Have UnpackingPCB Layout of the PCI-9111 PCI-9111s LayoutJumper Descriptions Hardware Installation OutlineConnectors Pin Assignment Device Installation for Windows Systems∙ CN 1 Digital Signal Input DI 0 ~ ∙ CN 3 Analog Input/Output, Extended I/O, Trigger Signals ∙ CN 2 Digital Signal Output do 0 ~Connect with ACLD-8125 Daughter Board ConnectionConnect with ACLD-9137 Connect with ACLD-9182PCI PnP Registers Registers FormatA/D Data Registers I/O Address MapAddress Write Read I/O AddressAddress Base + 0h Attribute read only Data Format A/D Channel Control RegisterBit Address Base + 6h Attribute write only Data Format BitA/D Channel Read Back Register A/D Input Signal Range Control RegisterAddress Base + 6h Attribute read only Data Format Bit Address Base + 8h Attribute write only Data Format BitA/D Range and Status Read back Register A/D Trigger Mode Control RegisterAddress Base + 8h Attribute read only Data Format Bit Address Base + 0Ah Attribute write only Data Format BitAddress Base + 0Eh Attribute write only Data Format Bit Mode DescriptionAddress Base + 0Ch Attribute write only Data Format Bit Hardware Interrupt Clear Register 12 A/D Mode & Interrupt Control Read Back RegisterAddress Base + 48h Attribute write only Data Format Bit Address Base + 0Ah Attribute read only Data Format BitAddress Base + 4h Attribute read only Data Format Bit Address Base + 4h Attribute write only Data Format BitAddress Base + 2h Attribute read only Data Format Address Base + 2h Attribute write only Data Format Bit 15 D/A Output RegisterAddress Base + 40h ~ Base + 46h A/D Conversion Operation Theorem2 A/D Signal Source Control 1 A/D Conversion ProcedureAnalog Input Signal Connection 3 A/D Trigger Source Control Signal RangeExternal Trigger EITS=1, TPST=don‘t care 4 A/D Data Transfer ModesFifo Half-Full Polling EOC Interrupt Transfer Pre-Trigger ControlTime FFF 6 A/D Data FormatInterrupt Control System Architecture IRQ Level SettingDual Interrupt System Extended Digital I/O Port Interrupt Source Control44mV 88mV D/A ConversionDigital Input and Output Timer/Counter Operation IntroductionPre-Trigger Counter Pacer Trigger Source4 I/O Address ++ Library Libraries InstallationData Types Programming Guide Naming Convention9111DO 9111Initial++ DOS ++ Windows9111DI 9111DOChannel9111EDI 9111DIChannel10 9111EDOReadBack 9111EDO11 9111SetEDOFunction 13 9111ADReadData 12 9111DA15 9111ADSetChannel 14 9111ADReadDataRepeat16 9111ADGetChannel Input Range Gain Gain Code 17 9111ADSetRange19 9111ADGetStatus 18 9111ADGetRange20 9111ADSetMode 22 9111INTSetReg 21 9111ADGetMode23 9111INTGetReg 24 9111ResetFIFO26 9111Set8254 25 9111ADSoftTrigger27 9111Get8254 28 9111ADTimer30 9111CounterRead 29 9111CounterStart31 9111CounterStop 32 9111INTSourceControl 34 9111GetIRQChannel 33 9111CLRIRQ36 9111ADFFHFPolling 35 9111GetIRQStatus38 9111ADHRAquire 37 9111ADAquire39 9111ADINTStart 40 9111ADFFHFINTStart ++ Library ∙61 42 9111ADFFHFINTStatus 41 9111ADINTStatus43 9111ADFFHFINTRestart 44 9111ADINTStop What do you need CalibrationVR Assignment A/D AdjustmentFunctions of VRs Bipolar Analog Output D/A Adjustment Unipolar Analog Output9111util Software UtilityRunning 9111util.exe System Configuration Calibration Function Testing Menu Window Functional TestingIeeprom Product Warranty/Service
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