National Instruments NI 6115, NI 6120 - page 61

Chapter 4 Connecting Signals

© National Instruments Corporation 4-23 NI 6115/6120 User Manual

selection for either rising or falling edge. The selected edge of TRIG2

initiates the posttriggered phase of a pretriggered DAQ sequence. In

pretriggered mode, the TRIG1 signal initiates the acquisition. The scan

counter indicates the minimum number of scans before TRIG2 can be

recognized. After the scan counter decrements to zero, it is loaded with the

number of posttrigger scans to acquire while the acquisition continues.

Thed evice ignores TRIG2 if it is asserted prior to the scan counter

decrementing to zero. After the selected edge of TRIG2 is received, the

device acquires a fixed number of scans and the acquisition stops. This

mode acquires data both before and after receiving TRIG2.

As an output, TRIG2 reflects the posttrigger in a pretriggered DAQ

sequence even if another PFI is externally triggering the acquisition.

TRIG2 is not used in posttriggered data acquisition. The output is an active

high pulse with a pulse width of 25to 50 ns. This output is set to

high-impedance at startup.

Figures4-16 and 4-17 show the timing requirements for TRIG2.

Figure 4-16. TRIG2 Input Signal Timing

Figure 4-17. TRIG2 Output Signal Timing

Rising-Edge

Polarity

Falling-Edge

Polarity

tw = 10 ns minimum

tw

tw

tw = 25 – 50 ns

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