Process data

EL515x - Illustration of the process data and structural contents

The plain text display of the bit meanings is particularly helpful not only in commissioning, but also for linking to the PLC program.
By right-clicking on the Status variable in the configuration tree (A), the structure can be opened for linking (B).
Activation of the Show Sub Variables button (C) displays all subvariables and links to the PLC (D) in the online view.

Selection of the operating mode - DC (Distributed Clocks)

The operating mode is selected via the DC tab in the Operating Mode dialog box. The supported operating modes are displayed in the selection dialog.

• FreeRun: the terminal operates frame-triggered. Cyclic operation is started via the SyncManagers of the EtherCAT frame processing.
• DC-Synchron: cyclic operation in the terminal is started by the local distributed clock at exact intervals. The start time is chosen such that it coincides with other output slaves in the EtherCAT system.
• DC-Synchron (input based): as DC-Synchron mode, with the cyclic start time chosen such that it coincides with other input slaves in the EtherCAT system.

EL515x - parameterization

An EL515x is parameterized via two dialog windows in the TwinCAT System Manager. Dialog box (A) shows the process data that can be parameterized based on the CoE directory (B).

• Changes to the process data-specific settings are generally only effective after a restart of the EtherCAT master: Restart TwinCAT in RUN or CONFIG mode; RELOAD in CONFIG mode
• Changes to the online CoE directory
• are in general immediately effective.
• are in general stored non-volatile only in the terminal/in the slave and should therefore be entered in the CoE StartUp list. This list is processed at each EtherCAT start and the settings are loaded into the slave.

Main PDO

The EL515x terminals offer two main PDOs per channel for the transmission of the basic process data.

The main PDO for the inputs contains the status data and a counter value (EL5152) / counter and latch value (EL5151). Counter and latch value are represented and transmitted as a 32-bit value or a 16-bit value, depending on the selection of the corresponding PDO.

The main PDOs for the outputs contain the control data and a value for setting the counter value. The value for setting the counter value is represented and transmitted as a 32-bit value or a 16-bit value, depending on the selection of the corresponding PDO.

Optional PDOs

A PDO with a 32-bit frequency value or a 32-bit period value can optionally be added to the main PDO per channel.

A 32-bit or 64-bit time stamp is available to the EL5151 as an additional PDO. The time stamp indicates the time of the last registered increment edge, based on the Distributed Clock system.

An overview of the available PDOs and their contents can be found in the System Manager (see fig. Selection dialog “Predefined PDO Assignment”, example of EL5151 D and E) or in the Section Operation modes.

Please observe the permissible combination possibilities (operation modes) when selecting the PDOs.

“Predefined PDO Assignment” selection dialog (from TwinCAT 2.11 build 1544 onwards)

The process data to be transmitted (PDO, ProcessDataObjects) can be selected by the user

• for all TwinCAT versions via the selection dialog “Predefined PDO Assignment” (see fig. Selection dialog “Predefined PDO Assignment”, example of EL5151 A) or
• selectively for individual PDOs (see fig. Selection dialog “Predefined PDO Assignment”, example of EL5151 B).

These changes become effective after activation and an EtherCAT restart or a reload.
Please observe the permissible combinations shown in the section Operation modes.

The following predefined PDOs are available with the EL515x

• Standard 16-bit (MDP 511) - EL5151 / EL5152
• Standard 32-bit (MDP 511) - EL5151 / EL5152
• Standard 16-bit (MDP) with 32-bit timestamp - EL5151, operation mode DC
• Standard 32-bit (MDP) with 64-bit timestamp - EL5151, operation mode DC

The contents of the Predefined PDO Assignment can be found in the section Operation modes or in the System Manager (see fig. Selection dialog “Predefined PDO Assignment”, example of EL5151 B, C).

Loss of links when changing the PDO In case of PDO changes, links already created in the changed objects are lost. When changing from Predefined PDO Assignment Standard 16-bit (MDP 511) to Standard 32-bit (MDP 511), for example, the already created links of the objects Counter value (index 0x6000: 11), Latch value (index 0x6000: 12) and Set Counter value (index 0x7000: 11) are deleted.