Configuring Keyboard Wedge Scanner Barcode Prefix Key

Applies to QEST Web App, QEST Administrator Console

This page describes the process to configure keyboard wedge barcode scanners to work with the QEST Web App

Overview

The QEST Web App can recognize barcodes or QR codes scanned directly by the camera on the client device but keyboard wedge scanners offer increased efficiency through significant faster scanning speeds.

This page describes the configuration necessary in the QEST Platform to allow the QEST Web App to recognize barcodes scanned by keyboard wedge scanners.

Scanners

While the majority of barcode scanners can be made to work with the QEST Web App there can be differences in

How the output of the scanner is able to be customized
How the scanner is programmed to modify the output
The implementation of how the scanners send the keyboard data back to the client device

The following section describes the expected scanner output format and the ability of scanners to meet these requirements should be confirmed prior to committing to a specific model of scanner.

Scanner Output Format

Keyboard wedge scanners appear as keyboards to the computer which they are attached to. This means that there must be some way for the QEST Web App to differentiate between keyboard input from a barcode scanner and normal user keyboard input. A special prefix key is defined and used in conjunction with a timer in order to achieve this.

When the QEST Web App recognizes that the Prefix key has been pressed it will then expect some text followed by the Enter key within a very short timeframe (shorter than a human could typing a barcode of useful length could typically achieve).

If these requirements are met, the barcode data, excluding the Prefix and Enter characters, is consumed and processed. Keyboard wedge barcode scanners must be programmed, therefore, to output data in the following format:

[Prefix][Barcode Content][Enter]

The Barcode Prefix Key Code in the QEST Platform

Barcode Prefix Key Recommendations

The prefix character is able to be configured via the QEST Administrator Console. The following are recommended when deciding on the key to be used:

The key should not be a printable character
The key should not be a character that modifies other keys on international keyboards (such as `)
The key should not have special functionality within the browser being used by users
The key needs to be able to be generated by the keyboard wedge barcode scanner being used

The F8 key is a good choice for the prefix key at the time of writing and is the default key assumed to be the prefix if no value is set in the QEST Administrator Console as described below.

Setting the Barcode Prefix Keycode

The QEST Administrator Console is used in order to configure the prefix key recognized by the QEST Web App in the Regions and Laboratories node.

While a different keycode can be set per-laboratory it is strongly recommended that only one keycode be configured at the (default) region for ease of rollout.

Navigate to the following node in the QEST Admininstrator Console: Configuration>Regions & Laboratories
In the Inherited Details frame, select the Options tab
Navigate to the Virtual key of the Barcode Header for QWA option and enter the appropriate keycode

This option requires the exact string that denotes the key used as the header. For instance F8 would need to be entered if the F8 key was the barcode header.

Keys and their values can be found here. Alternatively there exist websites, such as this one, which allow the user to press a key and see details about the javascript event details in full.

QEST Platform 5.7 Documentation