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Chapter 2 Hardware Overview of the NI 78x x © National Instruments Corporation 2-3 Mult ifunction Reconfigurable I/O User Manual Figure 2-3. NI 7831 /7833/784 x /785 x Block Diagram NI 7811 Over view The NI 7811 has 160 …

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Chapter 2 Hardware Overview of the NI 78xx
Multifunction Reconfigurable I/O User Manual 2-2 ni.com
Figure 2-2. NI 7830 Block Diagram
RTSI/PXI Triggers
PXI Local Bus (NI PXI-7830 only)
Connector 0 (MIO)
Connector 1 (DIO)
Input Mode Mux
AISENSE
AIGND
Calibration
Mux
Voltage
Reference
Temperature
Sensor
Calibration
DACs
2
x4 Channels
16-Bit
DAC
Digital I/O (16)
User-
Configurable
FPGA on RIO
Devices
Bus
Interface
Data/Address/
Control
Control
Address/Data
Flash
Memory
Configuration
Control
Configuration
PCI/PXI/CompactPCI Bus
16-Bit
ADC
Calibration
DACs
Input Mux
Digital I/O (40)
RTSI Bus
x4 Channels
Instrumentation
Amplifier
AI–
AI+
+
–
Chapter 2 Hardware Overview of the NI 78xx
© National Instruments Corporation 2-3 Multifunction Reconfigurable I/O User Manual
Figure 2-3. NI 7831/7833/784x/785x Block Diagram
NI 7811 Overview
The NI 7811 has 160 bidirectional DIO lines and a Virtex-II XC2V1000
FPGA.
NI 7813 Overview
The NI 7813 has 160 bidirectional DIO lines and a Virtex-II XC2V3000
FPGA.
NI 7830 Overview
The NI 7830 has four independent, 16-bit AI channels; four independent,
16-bit AO channels; 56 bidirectional DIO lines that you can configure
individually for input or output; and a Virtex-II XC2V1000 FPGA.
+
AI+
AI–
PCI/PXI/CompactPCI Bus
Input Mux
Instrumentation
Amplifier
Input Mode Mux
AISENSE
AIGND
16-Bit
DAC
x8 Channels
2
x8 Channels
Configuration
Flash
Memory
User-
Configurable
FPGA on RIO
Devices
Bus
Interface
Connector 1 (DIO)Connector 2 (DIO)
Data/Address/
Control
Digital I/O (16)
Digital I/O (40)
Digital I/O (40)
Calibration
DACs
Configuration
Control
Connector 0 (MIO)
Calibration
DACs
Voltage
Reference
–
16-Bit
ADC
Temperature
Sensor
Calibration
Mux
RTSI/PXI Triggers
RTSI Bus
Address/Data
Control
PXI Local Bus (NI PXI-783x only)
Chapter 2 Hardware Overview of the NI 78xx
Multifunction Reconfigurable I/O User Manual 2-4 ni.com
NI 7831/7833 Overview
The NI 7831/7833 each have eight independent, 16-bit AI channels; eight
independent, 16-bit AO channels; 96 bidirectional DIO lines that you can
configure individually for input or output; and a Virtex-II XC2V3000
FPGA.
NI 784x Overview
The NI 784x each have eight independent, 16-bit AI channels;
eight independent, 16-bit AO channels; and 96 bidirectional DIO lines that
you can configure individually for input or output. The PXI-7841 has a
Virtex-5 LX30 FPGA, and the PXI-7842 has a Virtex-5 LX50 FPGA.
NI 785x Overview
The NI 785x each have eight independent, 16-bit AI channels;
eight independent, 16-bit AO channels; and 96 bidirectional DIO lines that
you can configure individually for input or output. The PXI-7851 has a
Virtex-5 LX30 FPGA, the PXI-7852 has a Virtex-5 LX50 FPGA,
the PXI-7853 has a Virtex-5 LX85 FPGA, and the PXI-7854 has a Virtex-5
LX110 FPGA.
Analog Input (NI 783x /784x /785x Only)
You can sample NI 783x/784x/785x AI channels simultaneously or at
different rates. The input mode is software configurable, and the input
range is fixed at ±10 V. The converters return data in two’s complement
format. Table 2-1 shows the ideal output code returned for a given AI
voltage.
Table 2-1. Ideal Output Code and AI Voltage Mapping
Input Description AI Voltage
Output Code (Hex)
(Two’s Complement)
Full-scale range –1 LSB 9.999695 7FFF
Full-scale range –2 LSB 9.999390 7FFE
Midscale 0.000000 0000
Negative full-scale range +1 LSB –9.999695 8001