Configuring Equipment Drivers for the QEST Web App

Applies to QEST Web App

This article describes how to configure equipment drivers to allow for equipment interfacing in the QEST Web App.

Overview

Laboratory equipment often allows for electronic data collection, typically via an RS-232 or USB port. The QEST Web App can communicate with the equipment for the collection of data that would otherwise need to be typed in manually by an operator.

This article describes how to configure equipment drivers to allow for equipment interfacing in the QEST Web App.

“Drivers” contain the necessary logic to parse the format data that equipment sends to a PC via a serial port. Prior to undertaking this configuration the format of the data that the equipment item sends to the PC should be known.

The steps outlined in Obtaining Equipment Serial Port Settings and Output Format can be followed to determine this.

Equipment Drivers

One of the options in the QEST Web App Administration Page is the Equipment Drivers page.

This page lists all currently existing drivers in the current QEST Platform instance. A new driver can be added using the Add Driver button which will immediately open a new QEST Web App Driver Details page, as described below.

Clicking on a driver name will navigate to that driver’s QEST Web App Driver Details page, as described below.

Drivers can also be deleted from this page.

Deleting a driver here will mean that any equipment items using this driver will no longer be capable of interfacing data.

QEST Web App Driver Details

After clicking on an existing driver or adding a new driver, the user is presented with the details for that driver.

This page has two main sections, described below.

General Details and Driver Logic

General Details

The first set of fields are related to general information about the driver.

Name	The name of the driver that will be shown to users when it is selected on equipment items. The name should be made obvious so that the user knows where it should be selected (e.g. including some make/model information in the name could be useful). This is a mandatory field.
Equipment Type	A drop down field listing the equipment types that support QEST Web App equipment interfacing. The appropriate equipment type must be selected here. This is a mandatory field.
Equipment Make	The make of the equipment item, it is shown when selecting a driver on a particular equipment item. This is described in Configuring Equipment for Interfacing in the QEST Web App to assist with selecting the correct driver. This is an optional field.
Equipment Model	Same as above but the field is for the model of the equipment item. This is an optional field.
Equipment Year of Manufacture	Same as above but the field is for the manufacturing year for the equipment item. This is an optional field.
Driver Description	A brief description of the driver. Recommended details to include in this field are the date that it was created and a brief overview of what the driver logic is trying to achieve as well as the expected data flow.

Driver Logic

This section is where the logic of the driver is configured and these settings must be set appropriately or equipment interfacing will not function. The buttons above the fields contain descriptions of what should be included.

Request Value

Enter the data that the equipment driver should send to the equipment item to request a value. Leave blank if no request is to be made (e.g., the interface trigger is a manual input on the equipment item).

Special character sequences can be entered to send non-printable characters. For example:

\r will be sent as a carriage return
\n will be sent as a line feed
\xHH will be sent as a single character matching the ASCII code value HH (where H is a hexadecimal digit)
\\ will be sent as a single backlash

Regular Expression

A regular expression to match a subset of valid data from the stream that is returned, including an expected Header and Terminator.

The value will be taken by concatenating all capture groups within this regular expression into a single string and parsing this as a number.

It must meet the following requirements:
- Written as a JavaScript (ECMAScript) flavor regular expression
- Can contains multiple capturing groups which, when concatenated, match a raw numeric value
- Matches any specified header or terminator strings sent by the equipment (to avoid matches on partially transmitted data)

The following online resources can assist in constructing and testing regular expressions:

This page contains links to one or more external websites. These sites may contain software that is not authored, supported, or sold by Spectra QEST. As we have no control over the content of such sites, we take absolutely no responsibility whatsoever for any loss of data or other consequences that arise out of the visitation of the external website or the use of such software - direct or indirect.

Example driver logic for specific equipment models is available on QEST Web App Equipment Driver Examples.

Driver Testing

Once the driver is configured it can be tested directly from the details page to ensure it is functioning correctly prior to using on specific equipment items.

The appropriate COM port settings will need to be entered first:

After entering the correct serial port settings, pressing the Connect button will show a dialog to the user requesting that the appropriate COM port be selected. This should be the COM port that the equipment item is connected to.

After selecting the appropriate COM port and clicking Connect the Field for Equipment Interfacing will show a thick blue bottom border:

Navigating into this field will cause the equipment interfacing flow to take place. That is:

The request value, if any, is sent over the COM port
The QEST Web App waits for incoming data, which is indicated by the animation of the bottom border

If the driver is configured appropriately, sending data from the equipment item to the PC at this point should show the numeric value in the Field for Equipment Interfacing.

Troubleshooting Equipment Interfacing

If data does not appear in the interfaced field when it is sent from the equipment item it is possible to troubleshoot the data flow by pressing the space bar when in an interfaced field. This will show the manual interfacing dialog that can be used to inspect the data that the QEST Web App sent and received on the selected COM port.

This dialog can be useful in diagnosing any issues with the driver if the Received format is unexpected or if a connection issue exists, for example no data is being received.

The Accept button will be enabled if a valid numeric result was able to be parsed from the received data. Pressing this button will populate the field with the given value.

Read Again will clear any existing value, send any request value and wait for a new value to be received.

Decline will close the dialog and not change any existing value in the field.

Finalizing Configuration

After a successful test, the driver will need to be selected for use as part of the steps documented in Configuring Equipment for Interfacing in the QEST Web App.

QEST Platform 5.8 Documentation