Obtaining Equipment Serial Port Settings and Output Format

Applies to QEST Web App, QESTLab

Contents

Overview

For equipment to interface with QESTLab or the QEST Web App the format of data output from the equipment item must first be determined.

When interfacing with worksheets in QESTLab, an equipment driver is required that can read the specific format of output data. Spectra QEST has a number of equipment drivers available for various digital equipment devices to connect with QESTLab. In order to use one of the existing equipment drivers the output from the device will need to match the expected format.

When interfacing with worksheets in the QEST Web App, a system administrator will need to ensure that an appropriate driver has been configured to parse the output format appropriately.

In order to determine the format of data that is received from an equipment item over a serial connection, the equipment item should be connected to a PC via the port and serial communication software should be used to capture the output when the equipment item sends data to the PC.

RealTerm is one such software that can be used to capture serial port communications and will be the product described in this article. Any other software capable of capturing serial communication data would also suffice.

Capturing Output

To capture the device output from RealTerm follow the steps below:

1. Determine the COM port device the equipment is connected to.

   1. If the ports are physically on the PC, they should be marked in Windows Device Manager.

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   2. If the equipment is using virtual COM ports from a USB connection or adapter, the number will need to be determined appropriately from Windows Device Manager.
      
      

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2. Run RealTerm and configure the following Port tab settings (the equipment manual for each equipment device should contain appropriate configuration settings for the piece of equipment and instructions on how they can be set): 

   1. Baud

   2. Parity

   3. Data Bits

   4. Stop Bits

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3. Click Change when the Port tab settings have all been entered per the equipment device’s manual.

4. Click Open for RealTerm to start reading data from the equipment item to the PC. In some cases the equipment item will require additional steps to allow data to be sent to a PC such as pressing a Print button. In this scenario please contact the equipment manufacturer for further information on the process to send data from the equipment item to a PC.

5. When information is transferred from the device, RealTerm should capture the output. The output should appear in the main window similar to the example below. Note, the Status frame will also show data signals being sent and received by highlighting the appropriate pins with green indicators, as shown in the image below.

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6. To capture the output from RealTerm:

   1. Click on the Capture tab and select a File location by clicking the “…” button.

   2. Click the Start:Overwrite button to begin capturing data.

   3. Click the Stop Capture button to stop capturing data.

   4. Save the output to a text file.

   5. Alternatively, simply copy the output from the terminal screen above using the normal right click menu.
      
      

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Spectra QEST recommends capturing at least 3 or 4 readings per device and preparing a separate text file for each device that is to be interfaced.

Troubleshooting Data Capture

Problem	Check

Problem	Check
No communication observed in RealTerm	Correct serial cable type is being used (null modem or straight through - refer to the device manual for correct cable type). Correct COM port is selected in RealTerm. Balance and PC are correctly physically connected. If USB connector or adapter is being used, ensure virtual COM port exists. Ensure status indicators in RealTerm show activity when pressing  button. If not, try a different cable.
Communication in RealTerm appears distorted or is composed of NULL characters	The COM port, Baud, Parity, Data Bits and Stop Sit settings are likely incorrect. Check the setup of the equipment item and ensure the correct settings are being used in RealTerm. This will often require referencing the equipment device’s manual.
RealTerm Error – Port is already open when opening RealTerm or clicking Change Open	Another process is using the COM port. Ensure that only one instance of RealTerm is running.