QSB Software

The QSB software enables users to explore various features of the QSB product. The software and drivers have been designed and tested to only work on Windows 10 and 11.

US Digital Device Explorer

This download includes the US Digital Device Explorer which utilizes the .Net US Digital Device Library to scan for US Digital devices and display device specific configuration and status panels. US Digital devices are added...

QuickCheck

CPRQuickCheckforQSB.exe or “QuickCheck” provides the ability to test the output of any incremental encoder with Index with a QSB-S or QSB-D device. To use the program, follow the steps below. Plug your QSB into a USB port on...

USDigital .Net Libraries x64

This download contains the US Digital Device libraries that were compiled using the x64 and .Net framework 4.8 settings. Contents: USDigital.dll version 1.1.0.8 USDQSB.dll version 1.0.46.8 USDQSB_E version 1.0.1.3 USDT7...

READ MORE (Read me file)
DOWNLOAD usdigital_x64.zip (Version: 1.58.12 1/15/2024)

USDigital .Net Libraries AnyCPU

This download contains the US Digital Device libraries that were compiled with AnyCPU and .Net framework 4.8 settings. Contents: USDigital.dll version 1.1.0.8 USDQSB.dll version 1.0.46.8 USDQSB_E version 1.0.1.3 USDT7...

READ MORE (Read me file)
DOWNLOAD usdigital_anycpu.zip (Version: 1.58.12 1/15/2024)

QSB Scope

The initial release of the QSB Scope application configures a QSB-M device to stream analog input every 1.95ms and digital input when the input value changes (also limited to every 1.95ms). The resulting input is then...

QSB LabView 2010 Demo

The QSB_S LabView 2010 demo utilizes the USDQSB.dll .Net library to access an attached QSB device and read the encoder count value and perform basic encoder configuration. Note: the US Digital Device Explorer must be...

QSB Firmware Updater

The QSBFirmwareUpdater.exe provides the ability to update the firmware on a QSB device. The latest available firmware is embedded in this program. NOTE: The latest update of the QSBFirmwareUpdater includes:1. Fix for a...

QSB Linux Demo

DESCRIPTION ----------- The file streamQSB.c is provided as a demonstration c program of how to communicate with the QSB in a Linux environment. It was tested using Ubuntu 22.04.3 LTS (jammy) but should work similarly in...

READ MORE (Read me file)
DOWNLOAD qsb_linux_example.zip (Version: 1.02 1/15/2024)

QSB Python Demo

DESCRIPTION ----------- The file streamQSB.py is provided to demonstrate how to communicate with a QSB device. The progam displays a streamed encoder count value and a timestamp to the terminal until the user presses q or...

Related Content

QSB

QSB Manual Firmware Update Procedure

The file streamQSB.c is provided as a demonstration c program of how to

communicate with the QSB in a Linux environment. It was tested using

Ubuntu 22.04.3 LTS (jammy) but should work similarly in other Debian-

based distributions.

The program opens a USB serial port and configures is to communicate with a

QSB device at 230400 Baud, 8 data bits, no-parity, 1 stop bit. The QSB is then

configured to read an encoder in quadrature mode, X4 counter mode, index

disabled, modulo-N, counter enabled, and the counter preset register set to

1999. This will allow the counter to count up to 2000 pulses before

restarting at 0. The streaming interval is set to 0, enabling the QSB to

stream as fast as possible. The program can be modified to stream at other

interval rates divisible by 1.95 milliseconds. The Threshold register is

set to 1 so that streaming output occurs when the encoder value changes by 1.

The program displays the streamed count value and a timestamp to the terminal

until the user presses ESC or Ctrl-C. The timestamp displayed is the QSB's

timer counter that internally updates at a 1.95 ms interval. The display units

are in seconds. The timestamp counter starts at 0 when the device is powered on or

when the QSB receives a reset timestamp request. The demo resets the timestamp

after configuring the device.

The program depends on a hot/cold-plugging mechanism like udev to map the

QSB to a USB-to-serial device. The code assumes that no other USB tty

device is present and tries to open /dev/ttyUSB0. This may be a problem in

systems where other USB devices are present that also act as UARTs. Linux

is not deterministic in assigning node files to the scanned devices upon

boot; there is also a possibility that the QSB is plugged later on, when

an unknown number of devices may have been connected to the computer.

CREATING A SYMBOLIC LINK

------------------------

One way to deal with this issue is by creating a symbolic link in the /dev

directory with a predetermined node name that the code can safely use.

For example, /dev/qsb could be a predetermined link that refers to the

actual device assigned by the Kernel. The specific ways to do this vary

by distribution and by hot-plugging mechanism and are out of the scope

An example rules configuration file has been included called 99-usb-serial.rules.

This file should be placed in the /etc/udev/rules.d directory.

It is used to map a usb device that have been added to the system with a

specific idVendor of 0403 and idProduct of 6001 to a symbolic link call QSB-DEVICE.

The demo program assigns the SERIAL_PORT to the QSB-DEVICE symbolic link.

When a QSB device is plugged in, you should see ttyUSB0 and the symbolic link

QSB-DEVICE show up in the /dev directory.

Type cd /dev to switch to the /dev directory and ls to list the content of the directory.

For information on using udev to create the link automatically at boot or

at plug-in time, check the following resources:

- en.wikipedia.org/wiki/udev

- reactivated.net/writing_udev_rules.html

- ubuntuforums.org/showthread.php?t=168221

The following values for the QSB may be useful when configuring the

hot-plugging mechanism:

You may run into permission issues accessing the device. Rather than granting execute

permissions to ttyUSB0 or QSB-DEVICE, which comes and goes as the device is plugged

or unplugged, add yourself to the permission group the ttyUSB0 device belongs to.

To see the groups you are in, type: groups

To see all available groups, type: compgen -g

We are looking for the groups, tty and dialout.

To add yourself to the tty group, type: sudo usermod -a -G tty username

To add yourself to the dialout group, type: sudo usermod -a -G dialout username

The code is self-contained and does not need anything beyond stdlibc, so

the compilation should be straightforward:

gcc -o streamQSB streamQSB.c

Make sure to plug in the QSB before running the demo to avoid errors due to

a missing dev node. Depending on your particular setup, some modifications

to the code may be necessary.

If you prefer and integrated development environment, download and install VS Code.

https://code.visualstudio.com/Download.

The file streamQSB.py is provided to demonstrate how to communicate with a

QSB device. The progam displays a streamed encoder count value and a timestamp

to the terminal until the user presses q or Ctrl-C. The timestamp is the

elapsed time since the QSB timestamp was reset or since the application was

The demo has been tested to work on Windows 10, Linux Ubuntu 22.04.3 LTS

(jammy), and Raspberry Pi 4, but should work similarly in other Debian-based distributions.

The demo connects to an attached QSB and configures it to read an encoder in

quadrature mode, X4 counter mode, index disabled, modulo-N, counter enabled,

and the counter preset register set to 1999. This will allow the counter to

count up to 2000 pulses before restarting at 0.

A QSB can be configured to stream encoder count values to a host application

by writing values to the Threshold and Interval Rate registers and then submitting

a stream data request. In this demo, a value of zero is written to both registers.

The threshold represents the absolute change in value before a new output value is

reported. The Interval Rate sets the data output display rate in 1.9ms steps(1/512

Hz clock). For example, a value of 1 = 1.95 ms delay, 2 = 3.9 ms delay and so on.

--------------------------

A QSB device will enumerate on a Windows system as a virtual COM port.

The first time a QSB is recognized by the OS, it is assigned a COM port and

configured with a latency timer value of 16 msec. To optimize performance,

the latency timer should be changed from 16 to 1. To access the latency timer

value, open the Device Manager, select the appropriate COM port under the Ports

(COM & LPT) node, right-click and select properties. Select the Port Settings

tab and then click the Advanced... button. From the Latency Timer (msec)

drop-down list, select 1 and then click OK.