Supporting Modbus RTU and ASCII
Modbus protocol is very broadly implemented, mainly the serial versions of it (RTU and ASCII ones). The most common way of using Modbus is Modbus RTU. Are you developing software that communicates with electronic devices through Modbus RTU? In this case, you will surely appreciate a high-quality Modbus RTU software for monitoring and analysis of data sent via this protocol.
Serial Port Tester has an advanced option to monitor and analyze Modbus RTU and Modbus ASCII data packages. With this tool, you will have the ability to visualize Modbus data in a convenient way.
Why choose this serial testing software?
- Ease of use. The application was designed with the user in mind and provides an intuitive and user-friendly GUI. This facilitates the process of COM port testing, making this an effective tool for monitoring your system.
- Reliability. Stability is important in a software utility and Serial Port Tester offers that with its support for all versions of the Windows operating system. This includes the newest version of Windows 10 in both the x32 and x64 flavors. The internal drivers of the tool are digitally signed for your protection.
- Versatility. COM Port Tester can be a useful tool in a wide variety of situations. You can use it to monitor a single port or multiple interfaces simultaneously. Each monitored port’s data can be read, recorded, displayed, and saved for later analysis. The terminal allows you to emulate data transmission to a specified port using string, octal, decimal, binary, hexadecimal, or mixed formats.
How to test COM ports: step-by-step instructions.
For this demonstration, we will use Eltima’s Serial Port Tester as our COM port testing application. We will walk through a few typical use cases for the software.
First case: monitoring serial port activity
Use this procedure to monitor your system’s serial port activity.
- Download and install the program. Launch it and proceed to the next step to start a new monitoring session.
- From the main menu choose “Session > New session”, use the ‘Ctrl + N’ keyboard shortcut or click “New” on the toolbar.
- The “New monitoring session” window will be displayed.
You can now select the viewing mode which will be used to display the monitored serial data. The four choices are:
Line: displays IRP details in lines of plain text;
Dump: two-way serial data displayed in hexadecimal and string formats;
Terminal: presents the data as ASCII characters;
Table: recorded IRPs are displayed in a table.
“Select all” or “Select none” are other viewing options
- Select “Start monitoring now” to start monitoring right away and enable the “New window” option if that is where you want to conduct this session.
- Choose the events you want to monitor in the “Capture options” menu. You can select create/close, read/write, or device control.
- Click “Start monitoring” to begin the monitoring session.
If you want to save the session, select “Session -> Save session/Save session As” from the app’s main menu.
Second case: Resending data to a COM port
Reproducing the data flow between a serial interface and a serial application or device can be instrumental in testing and resolving problems. Using Serial Port Tester, you can repeatedly send identical serial data streams to observe the behavior of an app or device.
Follow these steps to send data to a serial port:
1. Open a current monitoring session or start a new one.
2. “Select Session>Reproduce” and configure the parameters that will be used in the transmission.
Use port - This parameter designates the COM port that will receive the reproduced data stream.
Send requests to this port - This option is enabled when you are sending data to a serial interface as if it is coming from a serial application.
Respond as a device - Use this option when you are sending data to a COM port on behalf of a serial device.
Preserve time intervals - Data packets will be sent with predetermined time intervals when this option is set.
Custom IO timeout - Define the Read/Write timeout parameters you will use for the session.
3. Click ”Start”
Third case: Compare monitoring sessions
Comparing two saved monitoring sessions can provide valuable information regarding your serial communication.
After you have saved the monitoring session using serial port test software you can compare it with another session to see the differences.
To achieve this, just do the following:
- Start or open a monitoring session.
- On the main menu, choose “Session>Compare Sessions”.
- Choose the monitoring file that will be used for the comparison.
- The sessions will be displayed side-by-side, making it easier for you to analyze the differences in the sessions.
Ways of implemented a loopback test.
What is loopback testing
A loopback test involves sending and receiving data from the same COM port. A signal is initiated from a device and returned to it after traversing part or all of a network.
What information does the loopback test provide?
The loopback test is providing information about:
- problems in a network of serial devices;
- ways to determine if a device is operating properly.
It’s an important method for troubleshooting serial communication problems and make sure that the COM port works correctly.
It often employed to address issues with RS232, RS422, and RS485 communications. You can emulate a communication circuit with a loopback test and eliminate the need for extra equipment to track down problems. Some modification of the port’s pins needs to be done in order to allow two-way communication on the same interface.