Setting the data transfer rate for PROFINET

The switched Ethernet interfaces X101 and X102 of the CX7293 support different data transfer rates. The data transfer rate is automatically detected for both interfaces and the faster data transfer rate is used by default.

However, it is possible for the two interfaces to have different data transfer rates, as the auto-detection function selects the best possible data transfer rate for both interfaces.

Example

If you connect one interface of the CX7293 to a switch that supports Gigabit Ethernet and the other interface to a 100 Mbit/s network, problems may occur. While the Gigabit interface signals a high bandwidth, data transmission is limited by the 100 Mbit/s interface. The CX7293 has to adjust the amount of data, which can lead to data loss or repeated transmissions. This increases the network load and exacerbates the problem.

It is recommended to set the data transfer rate so that both ports use the same data transfer rate. This avoids performance problems in the network.

Determining the currently used data transfer rate

The currently used data transfer rate of the interfaces can be called up via Diagnosis in the PROFINET device.

Setting the data transfer rate for PROFINET 1:
Pre-set data transfer rate for the Ethernet interfaces X101 and X102

Setting the data transfer rate under TwinCAT

The data transfer rate can be set manually for each interface in TwinCAT under the PROFINET tab and the Port Settings button.

Setting the data transfer rate for PROFINET 2:
Setting the data transfer rate under TwinCAT

Setting the data transfer rate via the PROFINET controller

Alternatively, the data transfer rate can also be set directly via the PROFINET controller. Please note that the settings should be made either via TwinCAT or via PROFINET to avoid conflicts.

Example (PROFINET controller in TwinCAT):

1. Open the corresponding device in the PROFINET controller project.
2. Select the desired port and navigate to the properties.
3. Select the desired data transfer rate under the MauType option.
Setting the data transfer rate for PROFINET 3:
Setting the data transfer rate via the PROFINET controller
4. Activate the Adjust MAU Type option and select the desired data transfer rate.
Setting the data transfer rate for PROFINET 4:
Setting the data transfer rate via the PROFINET controller, Adjust MAU Type

For PROFINET controllers from other manufacturers, refer to the manufacturer's documentation for the appropriate setting.