NI-Serial 21.5 Readme

January 2022

Thank you for using NI-Serial 21.5.

This file contains installation instructions and compatibility information for NI-Serial for Windows and LabVIEW Real-Time.

You can find more release information on

Parts of this document are relevant to only a full installation and do not apply to a runtime-only installation.

Supported Operating Systems

NI-Serial 21.5 supports the following operating systems:

  • Windows 10
  • Windows Server 2016
  • Windows Server 2019

NI-Serial 21.5 supports the following versions of the LabVIEW Real-Time Module:

  • LabVIEW Real-Time 2021
  • LabVIEW Real-Time 2020
  • LabVIEW Real-Time 2019
  • LabVIEW Real-Time 2018

To download previous versions of NI-Serial drivers, refer to and search for NI-Serial.

Note  Refer to Unsupported Windows Operating Systems for more information about support for Microsoft Windows OSes.

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Product Security and Critical Updates

Visit to view and subscribe to receive security notifications about NI products. For information about critical updates from NI, refer to Available Critical and Security Updates for NI Software.

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Supported Interfaces

Note  Refer to NI Serial Hardware for additional information about supported interfaces.

PCI Interfaces

  • PCI-8430/2
  • PCI-8430/4
  • PCI-8430/8
  • PCI-8430/16
  • PCI-8431/2
  • PCI-8431/4
  • PCI-8431/8
  • PCI-8432/2
  • PCI-8432/4
  • PCI-8433/2
  • PCI-8433/4

PCI Express Interfaces

  • NI PCIe-8430/2
  • NI PCIe-8430/8
  • NI PCIe-8430/16
  • NI PCIe-8431/2
  • NI PCIe-8431/8
  • NI PCIe-8431/16
  • NI PCIe-8432/2
  • NI PCIe-8433/2

PXI Interfaces

  • PXI-8430/2
  • PXI-8430/4
  • PXI-8430/8
  • PXI-8430/16
  • PXI-8431/2
  • PXI-8431/4
  • PXI-8431/8
  • PXI-8432/2
  • PXI-8432/4
  • PXI-8433/2
  • PXI-8433/4

PXI Express Interfaces

  • NI PXIe-8430/8
  • NI PXIe-8430/16
  • NI PXIe-8431/8
  • NI PXIe-8431/16

USB Interfaces

  • USB-232
  • USB-232/2
  • USB-232/4
  • USB-485
  • USB-485/2
  • USB-485/4

ExpressCard Interfaces

  • NI ExpressCard-8420/2
  • NI ExpressCard-8421/2

Windows Embedded Controllers

NI-Serial software is required to use any RS-485/422 ports on the following controllers. Any RS-232 ports are supported by Microsoft's serial driver and do not require NI-Serial to be installed.

  • cDAQ-913x
  • cRIO-908x
  • CVS-1458

Real-Time Controllers

  • Desktop RT
  • PXI Controllers

Serial C Series Modules1

  • NI 9870
  • NI 9871

1Serial C Series Modules may be used through NI-Serial and NI-VISA on backplanes configured to use NI-RIO IO Scan. To enable this support, NI-Serial 9870 and 9871 Scan Engine Support must be installed on the controller. For assistance with configuring a controller and backplane to use NI-RIO IO Scan, please refer to the NI-RIO documentation.

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LabVIEW NXG Support and Considerations

The following sections detail considerations for using LabVIEW NXG 5.0 with NI-Serial.

LabVIEW NXG Operating Systems and System Requirements

Software support for LabVIEW NXG differs in the following ways:

  • System requirements—Only 64-bit (x64) processors are supported.
  • Operating system—Only 64-bit operating systems are supported. Refer to the Supported Operating Systems section for more information.

LabVIEW NXG Hardware Support

Refer to the Supported Interfaces section for a list of hardware supported in LabVIEW NXG.


View context help in LabVIEW by pressing <Ctrl-H> and hovering over an object.

Search for items using the search bar in the upper right corner of the LabVIEW window. You can also view context help for the search results.

Additional documentation is available online at

LabVIEW NXG Examples

Launch LabVIEW and click the Learning tab.

LabVIEW lessons are located in the Lessons tab, and LabVIEW Examples are located in the Examples tab. Follow the instructions in the lessons and examples.

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Unsupported Windows Operating Systems

NI-Serial no longer supports Windows Vista/XP/7/8.x, Windows Server 2003/2008/2012, or any 32-bit Windows operating system. Versions of this product that ship after May 1, 2021, may not install or execute correctly on these operating systems. For detailed information about NI operating system support, visit

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Legal Information


© 1996–2022 National Instruments Corporation. All rights reserved.

Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National Instruments Corporation.

NI respects the intellectual property of others, and we ask our users to do the same. NI software is protected by copyright and other intellectual property laws. Where NI software may be used to reproduce software or other materials belonging to others, you may use NI software only to reproduce materials that you may reproduce in accordance with the terms of any applicable license or other legal restriction.

End-User License Agreements and Third-Party Legal Notices

You can find end-user license agreements (EULAs) and third-party legal notices in the following locations after installation:

  • Notices are located in the <National Instruments>\_Legal Information and <National Instruments> directories.
  • EULAs are located in the <National Instruments>\Shared\MDF\Legal\license directory.
  • Review <National Instruments>\_Legal Information.txt for information on including legal information in installers built with NI products.

U.S. Government Restricted Rights

If you are an agency, department, or other entity of the United States Government ("Government"), the use, duplication, reproduction, release, modification, disclosure or transfer of the technical data included in this manual is governed by the Restricted Rights provisions under Federal Acquisition Regulation 52.227-14 for civilian agencies and Defense Federal Acquisition Regulation Supplement Section 252.227-7014 and 252.227-7015 for military agencies.

IVI Foundation Copyright Notice

Content from the IVI specifications reproduced with permission from the IVI Foundation.

The IVI Foundation and its member companies make no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The IVI Foundation and its member companies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.


Refer to the NI Trademarks and Logo Guidelines at for information on NI trademarks. Other product and company names mentioned herein are trademarks or trade names of their respective companies.


For patents covering the NI products/technology, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your media, or the NI Patent Notice at