Slot groups of the EL3475

The EL3475 uses slot groups to improve ease of use and configurability. These slot groups can accommodate two different types of module groups and can be configured with TwinCAT in the Slots tab as either voltage or current power ports. The corresponding CoE entries and process data elements are adjusted accordingly. On delivery, the EL3475 is configured for voltage at port 0 and for current at the other ports.

The configuration of the slots follows the physical configuration of the four connections of the terminal, depending on the connected sensor (SVL or SCL). In the past, the use of such sensors required the manual configuration of sensor parameters, e.g. the transformer ratio. Thanks to TED (Transducer Electronic Data Sheet), the EL3475 supports the transmission of configuration data from the sensor to the terminal. This process can be triggered via commands (see table). Depending on the command, the parameters are automatically applied to the internal data flow (e.g. 0x800C, 0x801C, 0x802C for port 1).

During start-up, the terminal checks the physical sensor configuration and compares the values with the internally stored information. The results are displayed via diagnostic messages.

Distributed power measurement

The EL3475 uses distributed power measurement (DPM) to calculate power. It is therefore irrelevant for the function which port of an EL3475 in an EtherCAT segment supplies the voltage data for the respective current measurement port. By default, the terminal uses the first port as the source for all subsequent ports.

Via the objects

0x8060:11 (port 0)
0x8110:11 (port 1)
0x81C0:11 (port 2)
0x8270:11 (port 3)

the DPM voltage sources can either be set to another port of the terminal or to an external source. In this case, the DPM voltage data on PDO 0x1701 is used for the power calculation. The corresponding PDO PMD DPM Out (e.g. 0x1A26 for port 0) must be activated on the DPM main device side.