Serial Baud Rates Supported By NI-VISA

Overview

This document provides the supported baud rates when using NI-VISA for serial communication. 

Contents

Introduction

NI-VISA itself does not limit the range of baud rates you use. Instead, the baud rate request passes directly to the device driver for the serial interface. In LabVIEW, the baud rate is set using the VISA Configure Serial Port VI. If the baud rate set is not supported by the serial port, NI-VISA will return an error saying the attribute is not valid.

If you use NI-VISA on Linux or Mac OS, you usually are limited to the standard baud rates specified in this document. The standard driver on these operating systems does not support arbitrary baud rates.

To check whether a baud rate is supported by NI-VISA,

  1. Select the serial port of interest in Measurement and Automation Explorer) MAX and then Open VISA Test Panel.
  2. In the VISA Test Panel Configuration tab, enter the desired value into the Baud Rate field and select Apply Changes.

 

The Return Data field should return no error. If an unsupported value was used, the Return Data field will return hex error code 0xBFFF001E.

Refer to the tables below for the standard and maximum supported serial baud rates for NI serial hardware. 

Standard Baud Rates Supported by All NI Serial Ports

All NI serial hardware supports the following standard baud rates up to the maximum rate specified for the hardware. 

Standard Baud Rates (bps)

300

1200

14400

115200

600

2400

19200

230400

 

4800

38400

460800

 

9600

57600

 

Standard Baud Rates Supported by Some NI Serial Ports

Some NI serial hardware can support additional standard baud rates. Some hardware can also support any arbitrary baud rate up to its specified maximum rate. For more information on what your hardware supports, refer to the NI Serial Hardware Specifications and Features Guide

Additional Standard Baud Rates (bps)

110

28800

128000

 

56000

153600

 

 

256000

 

 

921600

 

Maximum Baud Rates for NI Serial Hardware

Hardware Models

Standard

Maximum Baud Rate (kbps)

NI 9870

RS-232

921.6

NI 9871

RS-422/485

3686.4

PCIe/PXIe-8430

RS-232

1000.0

PCIe/PXIe-8431

RS-422/485

3000.0*

USB-232

RS-232

230.4

USB-485

RS-422/485

460.8

ExpressCard-8420

RS-232

230.4

ExpressCard-8421       

RS-422/485

460.8



*The two-wire auto control mode for RS-485 transceiver control has a maximum baud rate of 2000 kbaud.

Standard Baud Rates (bps)
300 1200 14400 115200
600 2400 19200 230400
  4800 38400 460800
  9600 57600