Oversampling recordings with the TwinCAT 3 Scope

With the TwinCAT 3 Scope it is possible to represent oversampling values in a single variable. Since n values (n = oversampling factor) are recorded for each cycle when oversampling, the TwinCAT System Manager generates an ADS symbol containing a time stamp for each individual value. If a connection is made between the ADS symbol and the Scope, the Scope will accept all other settings to display the n values in the correct sequence.

So that the ADS symbol is created and can be directly scoped by an EtherCAT terminal (e.g. EL3702 or EL3632), some settings need to be made in the TwinCAT System Manager configuration:

In the EtherCAT process image the ADS tab of the ADS servers must be enabled, and the option Create symbols must be switched on. The assigned ADS port has to be specified later in the Scope in order to find the ADS symbols.

The desired oversampling factor should be set in the TwinCAT System Manager for the respective oversampling terminal before the configuration is activated.

If the configuration was loaded successfully and TwinCAT is in Run mode, the TwinCAT 3 Scope can be called. The server settings must be defined in the Target Browser of the Scope. The ADS port number assigned by the TwinCAT System Manager must be entered in the corresponding dialog and added with the Add, provided the port has not already been entered.

AdsPort of Image X (27905) appears in the Scope Target Browser. With this new entry, it is possible to browse the EtherCAT Terminals including the desired oversampling terminal. In the oversampling terminal, the variable shown in red with the supplement [T20] should be selected for the Scope recording. In this case 20 stands for 20 times oversampling. This number may vary according to the oversampling factor.

The INT16 variable can be recorded directly in TwinCAT Scope. In the following screenshot 20-fold oversampling with a cycle time of 1 ms.