Description
The National Instruments USB-7845R is a state-of-the-art Multifunction Reconfigurable I/O Device that comes with two part numbers: 783200-02 for the standard version and 783200-01 for the enclosed variant. This versatile device is equipped with 8 analog input (AI) channels, 8 analog output (AO) channels, and 48 digital input/output (DIO) channels, providing a comprehensive solution for various data acquisition needs.
Each AI channel includes three pins: AI+ for positive signal, AI- for negative signal, and AIGND for ground, supporting both differential and single-ended signals. Additionally, a special pin called AISENSE is available for connecting non-referenced single-ended signals.
For proper connectivity, referenced voltage signals should have their voltage GND connected to AI GND to maintain the common mode voltage within the specified range. Ground differential signals require the negative signal to be attached to AI- and the positive to AI+. When dealing with floating differential signals, one should connect the positive signals of the negative end to AI Ground using a 1 MΩ resistor.
The USB-7845R boasts an impressive maximum sampling rate of 500 kS/sec/channel, which allows for high-speed data acquisition and ensures that the device can meet the demands of sophisticated applications needing precise timing and synchronization.
| Attribute | Description |
|---|---|
| Manufacturer | National Instruments |
| Device | USB-7845R Multifunction Reconfigurable I/O Device |
| Part Numbers | 783200-02, 783200-01 (enclosed device) |
| Analog Input (AI) Channels | 8 AI Channels |
| Analog Output (AO) Channels | 8 AO Channels |
| Digital Input/Output (DIO) Channels | 48 DIO Channels |
| AI Channel Pins | AI+, AI-, AIGND |
| AISENSE Pin | For non-referenced single-ended signals |
| Connection for Referenced Signals | Connect voltage GND to AI GND |
| Connection for Ground Differential Signals | Connect negative signal to AI- and positive signal to AI+ |
| Connection for Floating Differential Signals | Connect positive signals of the negative end to AI Ground with a 1 MΩ resistor |
| Maximum Sampling Rate | 500 kS/sec/channel |
Question 1: What are the connection requirements for non-referenced single-ended signals on the National Instruments USB-7845R, and what is its maximum sampling rate per channel?
Answer 1: The recommended method for connecting floating differential signals to the AI ground on the National Instruments USB-7845R is by connecting the positive signals of the negative end to AI Ground using a 1 MΩ resistor to ensure proper function.
Question 2: What are the specifications and connection details for properly utilizing the analog input channels on the National Instruments USB-7845R Multifunction Reconfigurable I/O Device, and what is the maximum sampling rate it supports?
Answer 2: Non-referenced single-ended signals on the National Instruments USB-7845R require a connection to the special AISENSE pin, and the device’s maximum sampling rate per channel is 500 kS/sec.
Question 3: What types of signals do the analog input channels on the National Instruments USB-7845R support, and how should they be connected for proper functionality?
Answer 3: The National Instruments USB-7845R Multifunction Reconfigurable I/O Device features 8 analog input channels, each with AI+, AI-, and AIGND pins to support differential and single-ended signals, and an additional AISENSE pin for non-referenced single-ended signals; for proper connection, referenced signals must have their ground connected to AI GND, differential signals should connect the negative signal to AI- and the positive to AI+, and floating signals should be connected to AI Ground
Question 4: What is the recommended method for connecting floating differential signals to the AI ground on the National Instruments USB-7845R to ensure proper function?
Answer 4: The analog input channels on the National Instruments USB-7845R support both differential and single-ended signals; for proper functionality, differential signals should have the negative signal connected to AI- and the positive to AI+, while single-ended signals should have AI+ for the positive signal, AI- left unconnected, and AIGND for ground, with special consideration for non-referenced single-ended signals using the AISENSE pin for a proper connection.
Question 5: How should the Non-referenced single-ended signals be connected on the National Instruments USB-7845R to ensure proper functionality?
Answer 5: Non-referenced single-ended signals should be connected on the National Instruments USB-7845R by attaching the signal to the AI+ pin and connecting the AISENSE pin to the signal source ground to ensure proper functionality.
