Description
Product Overview
The NI PXI-6521 is an industrial digital I/O module designed for high channel isolation and industry-standard 24 V logic levels. It features 16 channels, including eight optically isolated digital input channels and eight non-latching relay output channels. This module is ideal for applications requiring high safety standards and precise control. The NI PXI-6521 includes a digital I/O watchdog feature that can switch to a configurable safe output state in case of a computer or application fault, ensuring detection and safe recovery from fault conditions. It also offers programmable power-up states, digital filtering, and change detection for optimal control over applications.
Technical Specifications
| Parameter Name | Parameter Value |
| Product Model | NI PXI-6521 |
| Manufacturer | National Instruments |
| Product Type | Industrial Digital I/O Module |
| Channels | 16 (8 digital inputs, 8 relay outputs) |
| Digital Inputs | ±30 VDC, 8 channels, optically isolated |
| Relay Outputs | 8 channels, non-latching, SPDT/SPST configuration |
| I/O Connector | 37-pin keyed male D-SUB |
| Maximum Working Voltage | Channel-to-channel: 150 V, Channel-to-earth: 150 V |
| Isolation | Channel-to-channel: 60 VDC continuous, Channel-to-bus: 150 V continuous, Channel-to-earth: 150 V continuous |
| Input Current | 11 V inputs: 4.5 mA/channel max, 30 V inputs: 12.5 mA/channel max |
| Propagation Delay | 45 μs typical |
| Relay Operate Time | 2 ms typical, 4 ms maximum |
| Expected Relay Life | Mechanical: 100,000,000 cycles, Electrical: varies by conditions |
| Power Requirements | 3.3 V (±5%): 100 mA max, 5 V (±5%): 300 mA typical, 500 mA max |
| Dimensions | 16 cm × 10 cm (6.3 in. × 3.9 in.) |
| Weight | 150.0 g (5.0 oz) |
| Operating Temperature Range | 0 °C to 55 °C |
| Storage Temperature Range | -20 °C to 70 °C |
| Relative Humidity | 10% to 90% noncondensing |
NI PX1-6521
Main Features and Advantages
High Safety Standards: The NI PXI-6521 requires a keyed connector and includes a digital I/O watchdog for safe output state switching in case of faults.
Programmable States: Offers programmable power-up states, digital filtering, and change detection for enhanced control.
Robust Isolation: Provides high channel isolation and industry-standard 24 V logic levels, ensuring reliable operation in demanding environments.
Versatile Configuration: Features eight optically isolated digital inputs and eight non-latching relay outputs, offering flexibility in system design.
Application Field
The NI PXI-6521 is widely used in industrial automation for precise control and monitoring of equipment. It is also suitable for laboratory testing environments where high safety and reliability are required. Additionally, it can be used in educational institutions for teaching and research purposes, providing a robust solution for digital I/O applications.
NI PX1-6521
Related Products
NI PXI-1031: A compatible PXI chassis that can be used with the NI PXI-6521 for high-performance applications.
LabVIEW: A graphical programming environment that can be used to control the NI PXI-6521 and develop data acquisition and control applications.
NI-DAQmx: Software for data acquisition and control, providing programming interfaces for LabVIEW, LabWindows/CVI, and Measurement Studio.
Installation and Maintenance
Pre-installation preparation: Before installing the NI PXI-6521, ensure you have the module, PXI chassis, and appropriate cables. Turn off the power and unplug the chassis. Install the module in the chassis and secure it with the provided screws. Connect the necessary cables and ensure all connections are secure.
Maintenance recommendations: Regularly inspect the connections for wear or damage. Clean the module using a soft, non-metallic brush to remove dust and ensure the device is completely dry before reusing it. Store the module in a dry place with relative humidity between 10% and 90% noncondensing.
Product Guarantee
The NI PXI-6521 is backed by a three-year warranty from National Instruments, ensuring the quality and reliability of the product. National Instruments also provides comprehensive after-sales service and technical support to assist customers with any issues or inquiries related to the product. This ensures that customers can use the module with confidence, knowing that they have access to reliable support and service from a reputable company.
