Configuration of the Subscriber
In the TwinCAT System Manager, a new box is added for the Subscriber under the RT Ethernet device.
Adding a Subscriber box and linking the network variables
A Subscriber box must be added under the RT Ethernet device.
A network variable is then created under the Subscriber box.
The link to a Publisher variable can be created automatically. First, you need to find the Publisher computer. All variables of this Publisher are then shown in a list.
Inputs and outputs were created under the added variable.
The FrameState input and the FrameCtrl output under the box indicate the current status (or control) of the received Ethernet frames. FrameState and FrameCtrl are reserved and are currently not supported.
The VarState input and the VarCtrl output under the network variable indicate the current status (or control) of the received network variable. VarState and VarCtrl are reserved and are currently not supported.
Quality of the network variables
The quality of a network variable is assessed on the Subscriber side. Two input variables are available for this purpose under the network variable. The Quality variable provides a counter with a resolution of 100 µs. The counter value indicates the variable delay. The example below shows the online value of Quality when the network connector is unplugged (counter increases) and reconnected (counter value 0).
In addition to the Quality variables, the CycleIndex variable is incremented in each Publisher cycle.
