DAQ DAQCard™-1200 User Manual Multifunction I/O Card for the PCMCIA Bus DAQCard-1200 User Manual December 2001 Edition Part Number 320936C-01
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Important Information Warranty The DAQCard-1200 is warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This warranty includes parts and labor.
Compliance FCC/Canada Radio Frequency Interference Compliance* Determining FCC Class The Federal Communications Commission (FCC) has rules to protect wireless communications from interference. The FCC places digital electronics into two classes. These classes are known as Class A (for use in industrial-commercial locations only) or Class B (for use in residential or commercial locations). Depending on where it is operated, this product could be subject to restrictions in the FCC rules.
Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations. Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada. Compliance to EU Directives Readers in the European Union (EU) must refer to the Manufacturer’s Declaration of Conformity (DoC) for information** pertaining to the CE Mark compliance scheme.
Contents About This Manual Conventions ...................................................................................................................xi National Instruments Documentation ............................................................................xii Chapter 1 Introduction About the DAQCard-1200.............................................................................................1-1 What You Need to Get Started ....................................................................
Contents Chapter 3 Connecting the Signals I/O Connector ................................................................................................................ 3-1 Signal Connection Descriptions .................................................................................... 3-3 Connecting Analog Input Signals ................................................................... 3-4 Types of Signal Sources ...................................................................
Contents Analog Output................................................................................................................4-10 Analog Output Circuitry..................................................................................4-10 Power-On State................................................................................................4-11 DAC Timing....................................................................................................4-11 Digital I/O ....................
About This Manual This manual describes the mechanical and electrical aspects of the National Instruments (NI) DAQCard-1200 and contains information concerning its installation and operation. The DAQCard-1200 is a compact, low-cost, low-power analog input (AI), analog output (AO), digital I/O (DIO), and timing I/O (TIO) card for IBM PC/XT, PC AT, and compatible computers that are equipped with a PCMCIA Type II PC Card socket.
About This Manual PC PC refers to all PC AT series computers with PCI or PXI bus unless otherwise noted. PCMCIA PCMCIA is an international standards body and trade association that promotes the interoperability of PC cards. Platform Text in this font denotes a specific platform and indicates that the text following it applies only to that platform. National Instruments Documentation The DAQCard-1200 User Manual is one piece of the documentation set for the data acquisition (DAQ) system.
1 Introduction This chapter discusses what you need to get started, optional software, optional equipment, how to unpack the DAQCard-1200, and safety information for using the device. About the DAQCard-1200 The DAQCard-1200 is a low-cost, low-power AI, AO, DIO, and TIO card for computers equipped with a Type II PC Card slot. The card contains a 12-bit, successive-approximation A/D converter (ADC) with eight inputs, which you can configure as eight single-ended or four differential channels.
Chapter 1 Introduction with the PC, is a versatile, cost-effective and portable platform for laboratory test, measurement, and control. The DAQCard-1200 is shipped with NI-DAQ, the NI driver software that handles every function listed on the data sheet for our hardware. Using NI-DAQ, you can start your application quickly and easily without having to program the card at the register level.
Chapter 1 Introduction NI-DAQ carries out many of the complex interactions, such as programming interrupts, between the computer and the DAQ hardware. NI-DAQ maintains a consistent software interface among its different versions so that you can change platforms with minimal modifications to your code. Whether you use LabVIEW, Measurement Studio, or other ADEs, your application uses NI-DAQ, as illustrated in Figure 1-1.
Chapter 1 Introduction National Instruments ADE Software LabVIEW features interactive graphics, a state-of-the-art interface, and a powerful graphical programming language. The LabVIEW Data Acquisition VI Library, a series of virtual instruments (VIs) for using LabVIEW with National Instruments DAQ hardware, is included with LabVIEW.
Chapter 1 Introduction Unpacking The DAQCard-1200 is shipped in an antistatic package to prevent electrostatic damage to the device. Caution Never touch the exposed pins of connectors. Because the DAQCard-1200 is enclosed in a fully shielded case, no additional electrostatic precautions are necessary. Remove the DAQCard-1200 from the package and inspect the device for loose components or any sign of damage. Notify NI if the DAQCard-1200 appears damaged in any way.
Chapter 1 Introduction • Pollution degree 3 means that conductive pollution occurs, or dry, nonconductive pollution occurs that becomes conductive due to condensation. Clean the product with a soft nonmetallic brush. Make sure that the product is completely dry and free from contaminants before returning it to service. You must insulate signal connections for the maximum voltage for which the product is rated. Do not exceed the maximum ratings for the product.
Chapter 1 • Introduction Installation category IV is for measurements performed at the source of the low-voltage (<1,000 V) installation. Examples of category IV are electric meters, and measurements on primary overcurrent protection devices and ripple-control units. Below is a diagram of a sample installation.
2 Installing and Configuring the DAQCard-1200 This chapter describes how to install and configure the DAQCard-1200. Installing the Software Install the software before you install the DAQCard-1200. Install the ADE, such as LabVIEW or Measurement Studio, according to the instructions on the CD and the release notes. After you have installed the ADE, install NI-DAQ according to the instructions on the CD and the DAQ Quick Start Guide included with the DAQCard-1200.
Chapter 2 Installing and Configuring the DAQCard-1200 3. Visually verify the installation by making sure that the DAQCard-1200 is fully inserted into the slot. 4. Attach the I/O cable. You can use either a 50-pin female or a 50-pin male cable to plug into the DAQCard-1200. For more information on these products, refer to the Optional Equipment section in Chapter 1, Introduction. Notice that the cable is keyed so that you can insert it only one way.
Chapter 2 Installing and Configuring the DAQCard-1200 Configuring the DAQCard-1200 Because of the NI standard architecture for data acquisition, the DAQCard-1200 is completely software configurable. Data acquisition-related configuration, which you must perform, includes such settings as analog input coupling and range, and others. You can modify these settings using NI-DAQ or application-level software, such as LabVIEW and Measurement Studio.
Chapter 2 Installing and Configuring the DAQCard-1200 Analog Input Polarity You can configure the AI setting on the DAQCard-1200 for either a unipolar range (0 to 10 V) or a bipolar range (–5 to +5 V). If you select a bipolar range, the two’s complement coding mode is selected. In this mode, –5 V input corresponds to F800 hex (–2,048 decimal) and +5 V corresponds to 7FF hex (2,047 decimal). If you select a unipolar mode, the straight binary coding is selected.
Chapter 2 Installing and Configuring the DAQCard-1200 Considerations for using DIFF input mode are discussed in Chapter 3, Connecting the Signals. Notice that the signal return path is through the negative terminal of the instrumentation amplifier and through channel 1, 3, 5, or 7 depending on which channel pair you select. RSE Input Mode (Eight Channels, Default Setting) RSE input mode means that all input signals are referenced to a common ground point that is also tied to the DAQCard-1200 AI ground.
Chapter 2 Installing and Configuring the DAQCard-1200 Analog Output Polarity The DAQCard-1200 has two channels of AO voltage at the front panel I/O connector. You can configure each AO channel for either unipolar or bipolar output. A unipolar configuration has a range of 0 to 10 V at the analog output. A bipolar configuration has a range of –5 to +5 V at the analog output. If you select a bipolar range for a D/A conversion, the two’s complement coding mode is selected.
Connecting the Signals 3 This chapter describes the signals on the DAQCard-1200 I/O connector. I/O Connector Figure 3-1 shows the pin assignments for the DAQCard-1200 I/O connector. This connector is attached to the ribbon cable that extends from the PC Card slot when the card is installed and the cable is connected.
Chapter 3 Connecting the Signals ACH0 ACH2 ACH4 ACH6 AISENSE/AIGND AGND DGND PA1 PA3 PA5 PA7 PB1 PB3 PB5 PB7 PC1 PC3 PC5 PC7 EXTUPDATE* OUTB0 OUTB1 CLKB1 GATB2 +5 V 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 ACH1 ACH3 ACH5 ACH7 DAC0OUT DAC1OUT PA0 PA2 PA4 PA6 PB0 PB2 PB4 PB6 PC0 PC2 PC4 PC6 EXTTRIG EXTCONV* GATB0 GATB1 OUTB2 CLKB2 DGND Figure 3-1.
Chapter 3 Connecting the Signals Signal Connection Descriptions Table 3-1 describes the connector pins on the DAQCard-1200 front I/O connector by pin number and gives the signal name and information about each signal connector pin. Table 3-1. Signal Descriptions Pins Direction Reference ACH<0..7> AI AGND Analog Channel 0 through 7—Analog input channels 0 through 7. 9 AISENSE/AIGND AI AGND Analog Input Sense/Analog Input Ground—Connected to AGND in RSE mode, analog input sense in NRSE mode.
Chapter 3 Connecting the Signals Table 3-1. Signal Descriptions (Continued) Pins Signal Name Direction Reference Description 44 GATB1 DI DGND Gate B1—External control signal for gating counter B1. 45 CLKB1 DI DGND Clock B1—External control clock signal for counter B1. 46 OUTB2 DO DGND Counter B2—Voltage output signal of counter B2. 47 GATB2 DI DGND Gate B2—External control signal for gating counter B2. 48 CLKB2 DI DGND Clock B2—External control clock signal for counter B2.
Chapter 3 Connecting the Signals Table 3-2. Bipolar and Unipolar Analog Input Signal Range Versus Gain Input Signal Range Gain Setting Bipolar Unipolar 1 ±5 V 0 to 10 V 2 ±2.5 V 0 to 5 V 5 ±1 V 0 to 2 V 10 ±500 mV 0 to 1 V 20 ±250 mV 0 to 500 mV 50 ±100 mV 0 to 200 mV 100 ±50 mV 0 to 100 mV How you connect analog input signals to the DAQCard-1200 depends on how you configure the card analog input circuitry and the type of input signal source.
Chapter 3 Connecting the Signals The instrumentation amplifier applies gain, common-mode voltage rejection, and high-input impedance to the AI signals connected to the DAQCard-1200. Signals are routed to the positive and negative inputs of the instrumentation amplifier through input multiplexers on the DAQCard-1200. The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals multiplied by the gain setting of the amplifier.
Chapter 3 Connecting the Signals The difference in ground potential between two instruments connected to the same building power system is typically between 1 mV and 100 mV but can be much higher if power distribution circuits are improperly connected. The connection instructions that follow for grounded signal sources eliminate this ground potential difference from the measured signal.
Chapter 3 Connecting the Signals You should use the DIFF input configuration when any of the following conditions are present: • Input signals are low level (less than 1 V). • Leads connecting signals to the DAQCard-1200 are greater than 15 ft. • Any input signal requires a separate ground-reference point or return signal. • The signal leads travel through noisy environments. Differential signal connections reduce noise pickup noise and increase common-mode noise rejection.
Chapter 3 Floating Signal Source 1 ACH 0 3 ACH 2 5 ACH 4 7 ACH 6 Connecting the Signals + Vs + – + Bias Current Return Paths 2 ACH 1 4 ACH 3 6 ACH 5 8 ACH 7 11 AGND – Vm Measured Voltage – Front I/O Connector DAQCard-1200 in DIFF Configuration Figure 3-3. Differential Input Connections for Floating Sources The 100 kΩ resistors shown in Figure 3-3 create a return path to ground for the bias currents of the instrumentation amplifier.
Chapter 3 Connecting the Signals Differential Connections for Grounded Signal Sources Figure 3-4 shows how to connect a ground-referenced signal source to a DAQCard-1200 configured for DIFF input mode. Refer to the Configuring Analog Input section of Chapter 2, Installing and Configuring the DAQCard-1200, for configuration instructions.
Chapter 3 Connecting the Signals Single-Ended Connection Considerations (RSE and NRSE Input Modes) Single-ended connections are those in which all DAQCard-1200 AI signals are referenced to one common ground. The input signals are tied to the positive input of the instrumentation amplifier, and their common ground point is tied to the negative input of the instrumentation amplifier. When the DAQCard-1200 is configured for single-ended input (RSE or NRSE), eight AI channels are available.
Chapter 3 Connecting the Signals Floating Signal Source 1 ACH 0 2 ACH 1 3 ACH 2 8 ACH 7 + Vs – + + 9 AISENSE/AIGND 11 AGND – Vm Measured Voltage – Front I/O Connector DAQCard-1200 in RSE Configuration Figure 3-5. Single-Ended Input Connections for Floating Signal Sources Single-Ended Connections for Grounded Signal Sources (NRSE Input Mode) If you measure a grounded signal source with a single-ended configuration, you must configure the DAQCard-1200 in the NRSE input configuration.
Chapter 3 GroundReferenced Signal Source 1 ACH 0 2 ACH 1 3 ACH 2 8 ACH 7 Connecting the Signals + Vs + – + Common-Mode Noise 9 AISENSE/AIGND 11 AGND – + Vcm Vm Measured Voltage – – Front I/O Connector DAQCard-1200 in NRSE Input Configuration Figure 3-6.
Chapter 3 Connecting the Signals –6 to +2 V in unipolar mode. Vin+ should remain within a range of –6 to +11 V in either mode. Connecting Analog Output Signals Pins 10 through 12 of the front connector are the AO signals DAC0OUT, AGND, and DAC1OUT. DAC0OUT is the voltage output signal for AO channel 0. DAC1OUT is the voltage output signal for AO channel 1. AGND is the ground-reference point for both AO channels and analog input.
Chapter 3 Connecting the Signals Connecting Digital I/O Signals The DAQCard-1200 DIO lines are not pulled up or pulled down. If you are using these lines as digital outputs, add 10 kΩ resistors to +5 V or DGND (depending on your application) to the DIO line(s) you are using. Caution Pins 13 through 37 of the front connector are DIO signal pins. DIO on the DAQCard-1200 uses the 82C55A integrated circuit. The 82C55A is a general-purpose peripheral interface containing 24 programmable I/O pins.
Chapter 3 Connecting the Signals Figure 3-8 illustrates signal connections for three typical DIO applications. Port C PC<0..7> 22 PB0 Port B PB<0..7> TTL Signal 29 PB7 +5 V 13 +5 V LED DGND Port A PA<0..7> 30 PA0 I/O Connector DAQCard-1200 Figure 3-8. Digital I/O Connections In Figure 3-8, port A is configured for digital output, and ports B and C are configured for digital input.
Chapter 3 Connecting the Signals Port C Pin Connections The signals assigned to port C depend on how the 82C55A is configured. In mode 0, or no-handshaking configuration, port C is configured as two 4-bit I/O ports. In modes 1 or 2, or handshaking configuration, port C is used for status and handshaking signals with zero, two, or three lines available for general-purpose I/O. Table 3-4 summarizes the port C signal assignments for each configuration.
Chapter 3 Connecting the Signals Timing Specifications Use the handshaking lines STB* and IBF to synchronize input transfers. Use the handshaking lines OBF* and ACK* to synchronize output transfers. The following signals are used in the timing diagrams shown later in this chapter: Name Type Description STB* Input Strobe Input—A low signal on this handshaking line loads data into the input latch.
Chapter 3 Connecting the Signals Mode 1 Input Timing Figure 3-9 shows the timing specifications for an input transfer in mode 1. T1 T2 T4 STB * T7 IBF T6 INTR RD * T3 T5 DATA Name Description Minimum Maximum T1 STB* pulse width 100 — T2 STB* = 0 to IBF = 1 — 150 T3 Data before STB* = 1 20 — T4 STB* = 1 to INTR = 1 — 150 T5 Data after STB* = 1 50 — T6 RD* = 0 to INTR = 0 — 200 T7 RD* = 1 to IBF = 0 — 150 All timing values are in nanoseconds. Figure 3-9.
Chapter 3 Connecting the Signals Mode 1 Output Timing Figure 3-10 shows the timing specifications for an output transfer in mode 1. T3 WRT* T4 OBF* T1 T6 INTR T5 ACK* DATA T2 Name Description Minimum Maximum T1 WRT* = 0 to INTR = 0 — 250 T2 WRT* = 1 to output — 200 T3 WRT* = 1 to OBF* = 0 — 150 T4 ACK* = 0 to OBF* = 1 — 150 T5 ACK* pulse width 100 — T6 ACK* = 1 to INTR = 1 — 150 All timing values are in nanoseconds. Figure 3-10.
Chapter 3 Connecting the Signals T1 WRT * T6 OBF * INTR T7 ACK * T3 STB * T10 T4 IBF RD * T2 T5 T8 T9 DATA Name Description Minimum Maximum T1 WRT* = 1 to OBF* = 0 — 150 T2 Data before STB* = 1 20 — T3 STB* pulse width 100 — T4 STB* = 0 to IBF = 1 — 150 T5 Data after STB* = 1 50 — T6 ACK* = 0 to OBF = 1 — 150 T7 ACK* pulse width 100 — T8 ACK* = 0 to output — 150 T9 ACK* = 1 to output float 20 250 T10 RD* = 1 to IBF = 0 — 150 All timing values are in nan
Chapter 3 Connecting the Signals Connecting Analog I/O and General-Purpose Timing Signals Pins 38 through 48 of the front connector are connections for timing I/O signals. The DAQCard-1200 timing I/O uses two 82C53 counter/timer integrated circuits. One circuit, designated 82C53(A), is used exclusively for DAQ timing, and the other, 82C53(B), is available for general use. You can use pins 38 through 40 and pin 43 to carry external signals for DAQ timing in place of the dedicated 82C53(A).
Chapter 3 Connecting the Signals Instead of using counter A0 as the sample-interval counter, you can use EXTCONV* to externally time conversions. Figure 3-13 shows the timing requirements for the EXTCONV* input. A falling edge on the EXTCONV* initiates an A/D conversion. tw VIH EXTCONV* tw tw 250 ns minimum VIL A/D Conversion Starts within 125 ns from this Point Figure 3-13.
Chapter 3 Connecting the Signals tw VIH td 50 ns minimum tw EXTTRIG tw 50 ns minimum VIL td First posttrigger sample EXTCONV* CONVERT Figure 3-14. Posttrigger DAQ Timing In the pretrigger mode, EXTTRIG serves as a stop-trigger signal. Data is acquired both before and after the stop trigger occurs. A/D conversions are software enabled, which initiates the DAQ operation. However, the sample counter is not started until a rising edge is sensed on the EXTTRIG input.
Chapter 3 Connecting the Signals tw VIH tw 50 ns minimum tw EXTTRIG VIL First posttrigger sample EXTCONV* CONVERT Figure 3-15. Pretrigger DAQ Timing Because both pretrigger and posttrigger modes use EXTTRIG input, you can only use one mode at a time. Therefore, you cannot use both a hardware start and a hardware stop trigger during the same acquisition. Figure 3-16 shows an example of a multiple-channel interval-scanning DAQ operation.
Chapter 3 Connecting the Signals OUTB1 tw = 50 ns td = 50 ns EXTCONV* CONVERT GATE ADC CH CH1 CH0 CH1 CH0 Figure 3-16. Interval-Scanning Signal Timing Analog Output Timing Connections Counter A2 is used to internally control updating the output voltage of the 12-bit DACs. In place of counter A2, you can use the final external control signal, EXTUPDATE*, to externally control updating the output voltage of the 12-bit DACs and/or to generate an externally timed interrupt.
Chapter 3 Connecting the Signals Figure 3-17 illustrates a waveform generation timing sequence using the EXTUPDATE* signal and the delayed update mode. The DACs are updated by a high level on the DAC OUTPUT UPDATE signal, which in this case is triggered by a low level on the EXTUPDATE* line. The counter-interrupt signal interrupts the computer. This interrupt is generated on the rising edge of EXTUPDATE*. The DACWRT signal writes a new value to the DAC.
Chapter 3 Connecting the Signals measurement. For these applications, the CLK and GATE signals at the front I/O connector control the counters. The single exception is counter B0, which has an internal 2 MHz clock. Refer to the DAQCard-1200 Register-Level Programmer Manual for programming information. The GATE, CLK, and OUT signals for counters B1 and B2 are available at the I/O front connector. The GATE and CLK pins are internally pulled up to +5 V through a 100 kΩ resistor.
Chapter 3 Connecting the Signals Pulsewidth measurement is performed by level gating. The pulse you want to measure is applied to the counter GATE input. The counter is loaded with the known count and is programmed to count down while the signal at the GATE input is high. The pulse width equals the counter difference (loaded value minus read value) multiplied by the CLK period. Perform time-lapse measurement by programming a counter to be edge gated.
Chapter 3 Connecting the Signals +5 V CLK OUT GATE Signal Source Gate Source Counter 13 DGND I/O Connector DAQCard-1200 Figure 3-19. Frequency Measurement Application Figure 3-20 shows the timing requirements for the GATE and CLK input signals and the timing specifications for the OUT output signals of the 82C53. DAQCard-1200 User Manual 3-30 ni.
Chapter 3 tsc tpwh Connecting the Signals tpwl VIH CLK VIL tgsu tgh VIH GATE VIL tgwh tgwl toutc toutg OUT VOH VOL tsc tpwh tpwl tgsu tgh tgwh tgwl toutg toutc clock period clock high level clock low level gate setup time gate hold time gate high level gate low level output delay from clock output delay from gate 380 ns min 230 ns min 150 ns min 100 ns min 50 ns min 150 ns min 100 ns min 300 ns max 400 ns max Figure 3-20.
Chapter 3 Connecting the Signals Pin 49 is fused for up to 1 A but should be limited to 250 mA. The fuse is a thermally resettable fuse which has an internal thermostat. This thermostat opens when the current exceeds 1 A and the temperature rises. After some time, the thermostat cools down, the switch closes, and the +5 V is available once more. Opening this fuse does not necessarily damage the DAQCard-1200. If you do not receive +5 V, check for any shorts between the +5 V power pin and ground.
4 Theory of Operation This chapter explains the operation of each functional unit of the DAQCard-1200. Functional Overview The block diagram in Figure 4-1 shows a functional overview of the DAQCard-1200.
Chapter 4 Theory of Operation The major components of the DAQCard-1200 are as follows: • PC Card I/O channel interface circuitry • AI circuitry • AO circuitry • DIO circuitry • Timing circuitry • Calibration circuitry The internal data and control buses interconnect the components. The rest of the chapter explains the theory of operation of each of the DAQCard-1200 components.
Chapter 4 Theory of Operation When you first insert the card into the computer, the system examines information stored in the DAQCard-1200 Card Information Structure (CIS). This data is used to configure the card appropriately for the system in which it is used. When the system has assigned the card to a section of memory, it updates the PC Card control registers and initializes the card.
Chapter 4 Theory of Operation GATEB2 CLKB2 GATEB2 CLKB2 General Purpose Counter OUTB2 OUTB2 GATEB1 GATEB1 CLKB1 MUX CLKB1 CLKA0 OUTB0 Scan Interval/ General Purpose Counter OUTB1 OUTB1 OUTB0 GATEB0 OUTB0 GATEB0 1 MHz Source MUX CTR WRT Data Timebase Extension/ General Purpose Counter 2 MHz Source 8 GATEB1 CLKB1 CLKB0 82C53 Counter/Timer Group B Sample Interval Counter Decode Circuitry I/O Connector CTR RD OUTB1 OUTB1 GATEB1 EXTCONV* A/D Conversion Logic EXTTRIG Sample Counter
Chapter 4 Theory of Operation Each 82C53 contains three independent 16-bit counter/timers and one 8-bit Mode Register. Each counter has a CLK input pin, a GATE input pin, and an OUT output pin. You can program all three counter/timers to operate in several useful timing modes. The first group of counter/timers is called Group A and includes A0, A1, and A2.
Chapter 4 Theory of Operation Data 12-Bit ADC 12 Mux Data GAIN0 Convert GAIN2 OUTB1 Gain Select/Mux Counter WRT/RD Dither Circuitry External Trigger Dither Enable DAQ Timing Counter/Timer Signals External Convert PCMCIA Interface 6 Dither EXTCONV* CONV AVAIL 8 GAIN1 EXTTRIG 12 1K Sample A/D FIFO Data 8 PCMCIA I/O Channel Sampleand-Hold Amp Decode Circuitry Programmable Gain Amp I/O Connector ACH0 ACH1 ACH2 ACH3 ACH4 ACH5 ACH6 ACH7 AISENSE/ AIGND A/D Data Output B1 Figure
Chapter 4 Theory of Operation The programmable gain amplifier applies gain to the input signal, allowing an analog input signal to be amplified before being sampled and converted, thus increasing measurement resolution and accuracy. The instrumentation amplifier gain is software-selectable. The DAQCard-1200 provides gains of 1, 2, 5, 10, 20, 50, and 100. The dither circuitry, when enabled, adds approximately 0.5 LSB rms of white Gaussian noise to the signal to be converted to the ADC.
Chapter 4 Theory of Operation Data Acquisition Timing A DAQ operation refers to the process of taking a sequence of A/D conversions when the sample interval, or the time between successive A/D conversions, is carefully timed. A finite DAQ operation acquires a finite number of samples, while a continuous DAQ operation acquires an infinite number of samples.
Chapter 4 Theory of Operation For an example of a multiple-channel interval DAQ operation, refer to the description of interval scanning signal timing in the Analog Input Timing Connections section of Chapter 3, Connecting the Signals. Data Acquisition Rates Maximum DAQ rates (number of samples per second) are determined by the conversion period of the ADC plus the sample-and-hold acquisition time.
Chapter 4 Theory of Operation The recommended acquisition rates in Table 4-2 assume that voltage levels on all the channels included in the scan sequence are within range for the given gain and are driven by low-impedance sources. If you use external conversions for single-channel acquisitions, the maximum sampling rate is 90 kS/s. Note Analog Output The DAQCard-1200 has two channels of 12-bit D/A output. Each AO channel can provide unipolar or bipolar output.
Chapter 4 Theory of Operation range of 0 to +10 V. A bipolar output gives an output voltage range of ±5 V. For unipolar output, 0 V output corresponds to a digital code word of 0. For bipolar output, –5 V output corresponds to a digital code word of F800 hex. One least significant bit (LSB) is the voltage increment corresponding to an LSB change in the digital code word. For both outputs: 10 1LSB = ------------ V 4096 Power-On State Both analog outputs reach 0 V approximately 110 ms after card insertion.
Chapter 4 Theory of Operation Digital I/O The DIO circuitry has an 82C55A integrated circuit. The 82C55A is a general-purpose programmable peripheral interface (PPI) containing 24 programmable I/O pins. These pins represent the three 8-bit I/O ports (A, B, and C) of the 82C55A, as well as PA<0..7>, PB<0..7>, and PC<0..7> on the DAQCard-1200 I/O connector. Figure 4-6 shows the DIO circuitry. DATA<0..7> 8 8 PC<0..
5 Calibration This chapter discusses calibrating the DAQCard-1200. NI-DAQ includes calibration functions for performing all the steps in the calibration process. Calibration refers to the process of minimizing measurement and output voltage errors by making small circuit adjustments. On the DAQCard-1200, these adjustments take the form of writing values to onboard calibration DACs (CalDACs). Some form of device calibration is required for most applications.
Chapter 5 Calibration This method of calibration is not very accurate because it does not take into account the fact that the device measurement and output voltage errors can vary with time and temperature. Self-calibrate the device when it is installed in the environment in which it is used. Self-Calibration The DAQCard-1200 can measure and correct for almost all of its calibration-related errors without any external signal connections. NI-DAQ provides a self-calibration function.
A Specifications This appendix lists the specifications for the DAQCard-1200. These specifications are typical at 25 °C unless otherwise noted. Analog Input Input Characteristics Number of channels ............................... 8 single-ended, 8 pseudodifferential, or 4 differential, software-selectable Resolution .............................................. 12 bits, 1 in 4,096 Max single-channel sampling rate .........
Appendix A Specifications Maximum working voltage (signal + common mode) ........................Negative input/AISENSE should remain within ±6 V (bipolar) or –6 to 2 V (unipolar) of AGND Overvoltage protection ...........................±35 V powered on and ±25 V powered off Inputs protected ......................................ACH<0..7> FIFO buffer size......................................1,024 samples Data transfers ..........................................Interrupts, programmed I/O Dither .........
Appendix A Specifications Input bias current ................................... ±100 pA Input offset current................................. ±100 pA CMRR .................................................... 70 dB, DC to 60 Hz Dynamic Characteristics Bandwidth Small signal (–3 dB) Gain Bandwidth 1–10 250 kHz 20 150 kHz 50 60 kHz 100 30 kHz Settling time to full scale step Accuracy Gain ±0.
Appendix A Specifications Stability Recommended warm-up time.................15 minutes Offset temperature coefficient Pre-gain............................................±15 µV/°C Post-gain ..........................................±100 µV/°C Gain temperature coefficient ..................±40 ppm/°C Analog Output Output Characteristics Number of Channels ...............................2 voltage Resolution ...............................................12 bits, 1 in 4,096 Max update rate ................
Appendix A Specifications Voltage Output Ranges .................................................... 0 to 10 V, ±5 V software selectable Output coupling...................................... DC Output impedance .................................. 0.5 Ω typ Current drive ......................................... 1 mA max per channel Protection ............................................... 80 mA momentary short-circuit protection to ground Power-on state 0 to 110 ms......................................
Appendix A Specifications Digital logic levels Level Min Max Input low voltage –0.3 V 0.8 V Input high voltage 2.2 V 5.3 V Output low voltage (Iout = 2.5 mA) — 0.4 V Output high voltage (Iout = –40 µA) (Iout = –2.5 mA) 4.2 V 3.7 V — — –10 µA 10 µA Output leakage current 0 ≤ Vout ≤ Vcc Protection................................................–0.5 to 5.5 V powered on, ±0.5 V powered off Handshaking ...........................................3 wire, 2 port Data transfers ..................
Appendix A Specifications Protection ............................................... –0.5 to 5.5 V powered on, ±0.5 V powered off Resolution Counters/timers ............................... 16 bits Compatibility ......................................... TTL Base clocks available ............................. 2 MHz Base clock accuracy ............................... ±50 ppm max Max source frequency ............................ 8 MHz Min source pulse duration......................
Appendix A Specifications Maximum Working Voltage Maximum working voltage refers to the signal voltage plus the common-mode voltage. Channel-to-earth .....................................30 VAC or 60 VDC, installation category I Channel-to-channel.................................30 VAC or 60 VDC, installation category I Environmental Operating temperature ............................0 to 50 °C Storage temperature ................................–55 to 150 °C Humidity .....................................
Appendix A Specifications To obtain the DoC for this product, click Declaration of Conformity at ni.com/hardref.nsf/. This web site lists the DoCs by product family. Select the appropriate product family, followed by your product, and a link to the DoC appears in Adobe Acrobat format. Click the Acrobat icon to download or read the DoC.
Differences among the Lab-PC+, the DAQPad-1200, and the DAQCard-1200 B This appendix contains a summary of the functional differences between the Lab-PC+, the DAQPad-1200, and the DAQCard-1200. The Lab-PC+ is a plug-in DAQ device for PCs. It has jumpers for allocating bus resources such as base address, interrupt, and DMA channels, as well as analog input/output resources such as input/output mode and polarity. It also has potentiometers for calibration.
Appendix B Differences among the Lab-PC+, the DAQPad-1200, and the DAQCard-1200 The following table summarizes the differences among the three products.
C Common Questions This appendix contains a list of common questions and answers relating to the operation of the DAQCard-1200. The questions are grouped according to the type of information requested. Installing and Configuring the DAQCard-1200 Which NI documentation should I read first to get started using DAQ software? Refer to the Configuring the DAQCard-1200 section in Chapter 2, Installing and Configuring the DAQCard-1200, for this information.
Appendix C Common Questions referenced to the same ground level as the DAQCard reference. Chapter 3, Connecting the Signals, outlines the various methods used to achieve the same ground level while maintaining a high CMRR. I want to use NI-DAQ to program the DAQCard-1200. How can I determine which NI-DAQ functions support the DAQCard? If you are using NI-DAQ 6.7 or later, refer to the NI-DAQ Function Reference Online Help file.
Technical Support Resources D Web Support NI Web support is your first stop for help in solving installation, configuration, and application problems and questions. Online problem-solving and diagnostic resources include frequently asked questions, knowledge bases, product-specific troubleshooting wizards, manuals, drivers, software updates, and more. Web support is available through the Technical Support section of ni.com. NI Developer Zone The NI Developer Zone at ni.
Appendix D Technical Support Resources Worldwide Support NI has offices located around the world to help address your support needs. You can access our branch office Web sites from the Worldwide Offices section of ni.com. Branch office Web sites provide up-to-date contact information, support phone numbers, e-mail addresses, and current events. If you have searched the technical support resources on our Web site and still cannot find the answers you need, contact your local office or NI corporate.
Glossary Prefix Meanings Value p- pico- 10 –12 n- nano- 10 –9 µ- micro- 10 – 6 m- milli- 10 –3 k- kilo- 10 3 M- mega- 10 6 G- giga- 10 9 t- tera- 10 12 Numbers/Symbols ° degrees Ω ohms % percent A A amperes A/D analog-to-digital AC alternating current ACH analog input channel signal ACK Acknowledge Input—A low signal on this handshaking line indicates that the data written from the specified port has been accepted; primarily a response from the external device that
Glossary ADC analog-to-digital converter—an electronic device, often an integrated circuit, that converts an analog voltage to a digital number ADE application development environment AGND analog output ground reference signal for analog output voltages AI analog input AIGND analog input ground signal AISENSE analog input sense signal AO analog output AWG American Wire Gauge B BCD binary-coded decimal bipolar a signal range that includes both positive and negative values (for example, –5
Glossary CMRR common-mode rejection ratio—a measure of an instrument’s ability to reject interference from a common-mode signal, usually expressed in decibels (dB) D D/A digital-to-analog DAC digital-to-analog converter DAQ data acquisition—(1) collecting and measuring electrical signals from sensors, transducers, and test probes or fixtures and inputting them to a computer for processing; (2) collecting and measuring the same kinds of electrical signals with A/D and/or DIO devices plugged into a co
Glossary DO digital output DOUT digital output signal E EEPROM electrically erasable programmable read-only memory—ROM that can be erased with an electrical signal and reprogrammed EISA Extended Industry Standard Architecture ESP Engineering Software Package EXTCONV external control signal to trigger A/D conversions EXTINT external interrupt signal EXTTRIG External Trigger—external control singal to trigger a DAQ operation EXTUPDATE External Update—external control singal to update DAC out
Glossary G gain The factor by which a signal is amplified, often expressed in dB.
Glossary L LED light-emitting diode LSB least significant bit M MAX Measurement and Automation Explorer—National Instruments software that allows you to interface with and configure NI devices MB megabytes of memory MSB most significant bit N NC not connected (signal) NI National Instruments NI-DAQ National Instruments driver software for DAQ hardware NRSE nonreferenced single-ended mode—all measurements are made with respect to a common (NRSE) measurement system reference, but the voltage
Glossary P PCMCIA an expansion bus architecture that has found widespread acceptance as a de facto standard in notebook-size computers. It originated as a specification for add-on memory cards written by the Personal Computer Memory Card International Association.
Glossary T TIO timing input/output TTL transistor-transistor logic two’s complement given a number x expressed in base 2 with n digits to the left of the radix point, the (base 2) number 2n – x U unipolar a signal range that is always positive (for example, 0 to +10 V) V V volts VAC volts, alternating current VCC positive supply voltage from the PCMCIA bus (usually +5V) VDC volts, direct current VI virtual instrument—(1) a combination of hardware and/or software elements, typically used wi
Index Symbols polarity configuration, 2-4 settings (table), 2-3 specifications amplifier characteristics, A-2 dynamic characteristics, A-3 input characteristics, A-1 stability, A-4 transfer characteristics, A-2 theory of operation, 4-5 analog input modes configurations differential connection considerations, 3-7 floating signal sources, 3-8 ground-referenced signal sources, 3-10 recommended input configurations (table), 3-7 DIFF definition (table), 2-4 purpose and use, 2-4 NRSE definition (table), 2-4 purp
Index C exceeding maximum input voltage ratings (caution), 3-4 floating signal sources, 3-6 ground-referenced signal sources, 3-6 input configurations, 3-7 instrumentation amplifier, 3-5 pins, 3-3 recommended input configurations (table), 3-7 single-ended connections floating signal sources (RSE configuration), 3-11 grounded signal sources (NRSE configuration), 3-12 purpose and use, 3-11 when to use, 3-11 types of signal sources, 3-6 analog output circuitry, 4-10 DAC timing, 4-11 polarity configuration, 2
Index D data acquisition timing connections See also general-purpose timing signal connections EXTCONV* signal, 3-23 EXTTRIG signal, 3-23 EXTUPDATE* signal, 3-26 multiple-channel interval scanning (figure), 3-26 pins, 3-22 posttrigger and prettrigger modes, 3-23 sample counter, 3-22 sample-interval counter, 3-22 waveform generation timing sequence, 3-27 DATA signal (table), 3-18 Developer Zone, E-1 DGND signal (table), 3-3, 3-4 diagnostic resources, E-1 DIFF input configuration, 2-4 definition (table), 2-
Index GATE signals general-purpose timing signal connections, 3-27 timing requirements signals (figure), 3-31 general-purpose timing signal connections See also data acquisition timing connections event-counting, 3-28 frequency measurement, 3-29 GATE, CLK, and OUT signals, 3-27 pins, 3-22 pulse generation, 3-28 pulsewidth measurement, 3-29 square wave generation, 3-28 time-lapse measurement, 3-29 timing requirements for GATE, CLK, and OUT signals (figure), 3-31 ground-referenced signal sources differential
Index NRSE input configuration, 2-5 definition (table), 2-4 recommended input configurations (table), 3-7 single-ended connections for ground-referenced signal sources, 3-12 floating signal sources differential connections, 3-8 recommended input configurations (table), 3-7 ground-referenced signal sources differential connections, 3-10 recommended input configurations (table), 3-7 installation, DAQCard-1200, 2-1 instrumentation amplifier, 3-5 interval scanning data acquisition multiple-channel interval sc
Index differential connections floating signal sources, 3-8 grounded signal sources, 3-10 single-ended connections, 3-11 when to use, 3-8 exceeding maximum input voltage ratings (caution), 3-4 floating signal sources, 3-6 ground-referenced signal sources, 3-6 input configurations, 3-7 instrumentation amplifier, 3-5 pins, 3-4 recommended input configurations (table), 3-7 single-ended connections floating signal sources (RSE configuration), 3-11 grounded signal sources (NRSE configuration), 3-12 when to use,
Index T I/O connector exceeding maximum ratings (caution), 3-1 pin assignments (figure), 3-2 signal descriptions (table), 3-3 signal descriptions, 3-3 single-ended connections floating signal sources (RSE configuration), 3-11 ground-referenced signal sources (NRSE configuration), 3-12 when to use, 3-11 software programming choices National Instruments ADE software, 1-4 NI-DAQ driver software, 1-2 specifications analog input amplifier characteristics, A-2 dynamic characteristics, A-3 input characteristics,
Index U W unpacking the DAQCard-1200, 1-5 Web support from National Instruments, E-1 worldwide technical support, E-2 WRT* signal (table), 3-18 V voltage output specifications, A-5 DAQCard-1200 User Manual I-8 ni.
