Manuals / Brands / Computer Equipment / Switch / National Instruments / Computer Equipment / Switch

National Instruments NI 6115, NI 6120 Analog Output, Analog Trigger

1 127

Download 127 pages, 1.22 Mb

Chapter 3 Hardware Overview

© National Instruments Corporation 3-5 NI 6115/6120 User Manual

Analog Output

The NI6115/6120 supplies two channels of AO voltage at the I/O

connector. The range is fixed at bipolar ±10 V.

The AO channels on the NI6115 contain 12-bit DACs that are capable of

4MS/s for one channel or 2.5 MS/s for each of two channels. The NI 6120

DACs are 16-bit, and they have the same AO capabilities as the NI6115.

Refer to AppendixA, Specifications, for more detailed inform ation about

the AO capabilities of the NI6115/6120.

Note The AO channels do not have analog or digital filtering hardware and do produce

images in the frequency domain related to the update rate.

The NI6115/6120 includes high-density memory modules allowing for

long waveform generations.

Analog Trigger

In addition to supporting internal soft ware triggering and external digital

triggering to initiate a DAQ sequence, these devices also support analog

hardware triggering. You can configure the analog trigger circuitry to

accept either a direct analog input from the PFI0/TRIG1 pin on the

I/Oconnector or a post-gain signal from the output of the PGIA on any of

the channels, as shown in Figure 3-3. The trigger-level range for the direct

analog channel is ±10 V with a resolution of 78 mV for the NI6115 and

4.88 mV for the NI6120. The input impedance for the direct analog

channel is 10kΩ. When this direct analog channel is configured for AC

coupling, the corner frequency is 159 Hz.

The range for the post-PGIA trigger from a selected channel is the

full-scale range of the selected channel with a resolution of that range

divided by 256 for the NI6115 and 4,096 for the NI 6120.

Two trigger reference signals, lowValue and highValue, can then be

independently set to achieve advanced triggering modes. Refer to

Figures3-3 through 3-8 for illustrations of these modes.

Note The PFI0/TRIG1 pin is an analog input when configured as an analog trigger.

Therefore, it is susceptible to crosstalk from adjacent pins, which can result in false

triggering when the pin is left unconnected. To avoid false triggering, make sure the

PFI0/TRIG1 pin is connected to a low-impedance signal source (less than 1kΩ source

impedance) if you plan to enable this input using software.

Contents

Main Page Important Information Warranty Copyright Trademarks Patents Compliance FCC/Canada Radio Frequency Interference Compliance Determining FCC Class FCC/DOC Warnings Class A Compliance to EU Directives Contents Chapter 4 Connecting Signals Page About This Manual Conventions National Instruments Documentation Related Documentation Introduction About the NI 6115/6120 Using PXI with CompactPCI What You Need to Get Started Software Programming Choices NI-DAQ National Instruments ADE Software Optional Equipment Custom Cabling Unpacking Safety Information Page Page Installing and Configuring the NI 6115/6120 Installing the Software Installing the Hardware Page Configuring the Device National Instruments Corporation 3-1 NI 6115/6120 User Manual Hardware Overview DAQ - STC RTSI Bus Figure 3-1. NI 6115 Block Diagram Analog Input The following sections describe in detail each AI category. Input Mode Note The inputs are differential only in the sense that the ground loops are broken. I/O Connector Input Polarity and Input Range Considerations for Selecting Input Ranges Input Coupling Analog Output Analog Trigger Figure 3-3. Analog Trigger Block Diagram for the NI 6115/6120 Figure 3-4. Below-Low-Level Analog Triggering Mode Page Antialiasing Filters Phase-Locked Loop Circuit Correlated Digital I/O Timing Signal Routing Page Programmable Function Inputs Device and RTSI Clocks RTSI Triggers Page Figure 3-13. PXI RTSI Bus Signal Connections Connecting Signals I/O Connector Figure 4-1. I/O Connector Pin Assignment for the NI 6115/6120 I/O Connector Signal Descriptions Table 4-2. Signal Descriptions for I/O Connector Pins Table 4-2. Signal Descriptions for I/O Connector Pins (Continued) Table 4-3. Analog I/O Signal Summary for the NI 6115 Table 4-2. Signal Descriptions for I/O Connector Pins (Continued) Table 4-4. Analog I/O Summary for the NI 6120 Table 4-5. Digital I/O Signal Summary Types of Signal Sources Floating Signal Sources Table 4-5. Digital I/O Signal Summary (Continued) Ground-Referenced Signal Sources Connecting Analog Input Signals Connections for Ground-Referenced Signal Sources * Figure 4-2. Pseudodifferential Input Connections on the NI 6115 forGro und-Referenced Signals Figure 4-3. Pseudodifferential Input Connections on the NI 6120 forGro und-Referenced Signals Connections for Nonreferenced or Floating Signal Sources * Figure 4-4. Differential Input Connections on the NI 6115 for Nonreferenced Signals Common-Mode Signal Rejection Considerations Working Voltage Range Connecting Analog Output Signals Connecting Digital I/O Signals Correlating DIO Signal Connections Page Power Connections Connecting Timing Signals Page Programmable Function Input Connections DAQ Timing Connections TRIG1 Signal TRIG2 Signal Page STARTSCAN Signal Page CONVERT* Signal AIGATE Signal SISOURCE Signal SCANCLK Signal EXTSTROBE* Signal Waveform Generation Timing Connections WFTRIG Signal UPDATE* Signal UISOURCE Signal General-Purpose Timing Signal Connections GPCTR0_SOURCE Signal GPCTR0_GATE Signal GPCTR0_OUT Signal GPCTR0_UP_DOWN Signal GPCTR1_SOURCE Signal GPCTR1_GATE Signal GPCTR1_OUT Signal Figure4-34 shows the timing requirements for GPCTR1_OUT. Figure 4-35. GPCTR1_OUT Signal Timing Figure 4-36. GPCTR Timing Summary GPCTR1_UP_DOWN Signal FREQ_OUT Signal Field Wiring Considerations Calibration Loading Stored Calibration Constants Self-Calibration External Calibration Page A Specifications Analog Input Input Characteristics DC Transfer Characteristics Table A-1. NI 6115 Analog Input DC Accuracy Information Table A-2. NI 6120 Analog Input DC Accuracy Information Dynamic Characteristics Table A-4. NI6120 Analog Input Dynamic Charac teristics Figure A-1. NI 6115 Total Harmonic Distortion Plus Noise (THD+N) Figure A-2. NI 6120 Total Harmonic Distortion Plus Noise (THD+N) Figure A-3. NI6115 High-Voltage THD + N Figure A-4. NI 6120 High-Voltage THD+ N Figure A-5. NI 6115 THD + N with Filters Stability Analog Output Output Characteristics DC Transfer Characteristics Voltage Output Dynamic Characteristics Stability Digital I/O Timing I/O Triggers Analog Trigger Page Safety Maximum Working Voltage Electromagnetic Compatibility B Common Questions General Information Installing and Configuring the Device Analog Input and Output Page Timing and Digital I/O Page C Technical Support and Professional Services Glossary Numbers/Symbols A B C D E F G H I K L M N O P R S T U V W Index Numerics A B C D E F G H I K L M N O P Q R S Page T U V W