Anonymous Verified Buyer
" Very responsive and helpful, competitive pricing. Good source! "
July 2025
USB-8451
NI USB-8451, 8 Digital I/O Lines, Bus-Powered, I2C/SPI Interface Device
Actual item may vary if no part number is provided on quote request.
✔ 2 Year Warranty Included
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✔ NIST Calibration Available
Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
Carol Zimme**** Verified Buyer
" Very responsive and helpful, competitive pricing. Good source! "
July 2025
Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
National Instruments USB-8451 I2C/SPI Interface Device
The USB-8451 (Part Numbers: 779553-50, 779553-01, 192317D-02, and 192317D-02L) is a bus-powered, full-speed I²C/SPI interface device from National Instruments. This device is made to connect to and communicate with integrated circuits (I2C), peripheral interface devices, and system management buses. With its eight digital I/O lines, the NI USB-8451 Interface Device is a portable communication solution intended for use with consumer electronics and integrated circuits. Each of these lines may be configured independently to function as a static digital input or output line. In addition, they can be utilized in a variety of applications such as I2C device configuration or toggling LEDs. The I/O connectors of this interface device include a USB series B receptacle and two 16-position screw terminal plug headers.
The NI USB-8451 Interface Device, in contrast to PCI interfaces, may be utilized in close proximity to I2C/SPI devices, which minimizes noise issues and the length of the I2C bus. The NI USB-8451 is a self-sufficient device, meaning it doesn't require an external power source. Rather, the full-speed USB interface typically offers 80 mA of power with a 500 mA maximum. To protect against potential damage, this interface device offers integrated protection against overcurrent, overvoltage, and undervoltage conditions on each SPI, DIO, and SPI CS signal. There are four SPI modes and an advanced API for custom I2C and SPi transactions.
Intended for indoor use only, the NI USB-8451 should be operated within a temperature range of 0 °C to 45 °C, and it can be kept within a storage temperature range of 40 °C to 85 °C. Without connectors attached, the NI device measures 6.35 cm × 8.51 cm × 2.31 cm (2.50 in. × 3.35 in. × 0.91 in.) in dimensions. With connectors included, the dimensions measure 8.18 cm × 8.51 cm × 2.31 cm (3.22 in. × 3.35 in. × 0.91 in.). In total, the NI USB-8451 Interface Device weighs 84 g (3 oz).
The NI USB-8451 has been declared obsolete by National Instruments, but the interface device will remain available for repair or purchase in perpetuity with Apex Waves.
| Model | USB-8451 |
|---|---|
| Manufacturer | National Instruments |
| Part Numbers | 779553-50, 779553-01, 192317D-02, 192317D-02L |
| Type | I2C/SPI Interface Device |
| Digital I/O Lines | 8 |
| Maximum I2C Clock Rate | 250 kHz |
| Maximum SPI Clock Rate | 12 MHz |
| Screw Terminal Wiring | 16 AWG to 28 AWG |
| I/O Connectors | USB Series B Receptacle, 2 16-Position Plug Headers (Screw Terminal) |
| Operating Temp Range | 0 °C to 45 °C |
| Storage Temp Range | -40 °C to 85 °C |
| Dimensions | Without Connectors: 2.50 in. × 3.35 in. × 0.91 in. (6.35 cm × 8.51 cm × 2.31 cm) With Connectors: 3.22 in. × 3.35 in. × 0.91 in. (8.18 cm × 8.51 cm × 2.31 cm) |
| Weight | 3 oz. (84 g) |
| USB-8451 Manual | User Manual and Maintenance Manual Available for Download |
| Price | Request a Quote |
Associated part numbers for USB-8451:
National Instruments USB-8451 Frequently Asked Questions
Question: What is the difference between the two part numbers for the USB-8451?
Answer: The first part number, 779553-50, is board only (not an enclosed device). However, the second part number, 779553-01, is an enclosed device.
Question: What driver is used with the NI USB-8451?
Answer: The NI driver used is NI-845x.
Question: What are the power requirements for the NI USB-8451?
Answer: The power requirements are typically 80 mA but 500 mA maximum for 4.10 to 5.25 VDC. It is 300 µA for standby mode and 500 µA maximum for USB suspend.
Question: What is the output driver type on the NI USB-8451?
Answer: The output driver type on the interface device is push-pull (active drive) or open-drain, software selectable.
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