> For the complete documentation index, see [llms.txt](https://support.powerio.com/hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.powerio.com/hub/blog/en/news-blog/fehlersuche-mit-der-modbus-log-funktion.md).

# Troubleshooting with the Modbus log function

## Description

The Modbus log function of the powerIO-Box T1.B100 records all Modbus messages and displays them clearly. With various filtering options you can search specifically for errors. This is particularly helpful during commissioning and maintenance of systems with multiple Modbus devices.

## **Functionality in detail**

The Modbus log function of the powerIO-Box T1.B100 offers a variety of practical features specifically tailored to the needs of technicians and system integrators.

<figure><img src="/files/94d9deaad77614b8ce628c3fb7ed15ca53b95c84" alt=""><figcaption></figcaption></figure>

#### **Live view with filters**

* All Modbus requests are recorded and displayed automatically
* Various filter options allow targeted searches by Unit IDs, function codes, register addresses or serial ports
* With the status filter you only see faulty messages - saving time when troubleshooting

#### **Fast troubleshooting**

* Devices that do not respond are shown immediately (Exception Code 11)
* Incorrect register addresses are identified immediately by Exception Code 02 (Illegal Data Address)
* The processing time display helps identify performance issues in the network

#### **Export data**

* The log data can be exported as a CSV file
* Convenient for documentation or support requests

#### **Automatic deactivation**

* Logging automatically deactivates after a predefined time to conserve system resources

#### **Monitor multiple serial ports**

* Works with all four serial ports of the T1.B100
* Also possible with port 5 when using an expansion card
* Each port can be viewed individually

With the Modbus log function you can find problems in Modbus networks faster and fix them specifically.

Further information and detailed instructions can be found in the [manual](/hub/en/t1.b100/feldbus-protokolle/modbus.md#modbus-log) .


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