This page demonstrates how to create different task sequences that are associated with and executed by an outside signal transmitted via TCP/IP.

Contents

Overview


The goal of this tutorial is to provide a starting point for creating different task sequences, that are depending on and related to external signals such as a PLC, a barcode scanner, or an external vision.

These different task sequences will only be executed, if a specific signal is transmitted. To establish such a task, Do-If nodes can be used to retrieve which specific sequence shall be executed. 


As an example, three different task sequences have been implemented, which are executing various moves of the robot, in case their specific task is requested to be executed by an external signal. The overview of the task is given below. Additionally, the example task can be downloaded here.



Task structure


Lets break down the task:


The whole task is divided into three different subtasks, which are only executed, if the desired Do-If node meets the predefined conditions. All three Do-If nodes are retrieving the status of the Signal_Putty_IN which is transmitted via TCP/IP. 




The respective subtask is only executed, if the external signal is sending the corresponding value (eg. 1, 2, or 3), which is triggering the appropriate Do-If node. If the values are not matching, the robot will not execute any of the subtasks which are located in the branch of a Do-If node. Since the value of the Signal_Putty_IN is reset during the initializing phase, the default value is 0 and is therefore not triggering any of the Do-If branches while starting the task.

After the task has been started, the Do-If nodes can be triggered by the external signal Signal_Putty_IN. In case Signal_Putty_IN will be changed to 1, the first branch will be executed, the Signal_Putty_IN will be reset to 0 again and the robot will move in a vertical line.



In case Signal_Putty_IN will be set to 2, the second Do-If node will be triggered and executes the underlying branch. There, the signal will be reset first and the robot is moving horizontally. 



If the Signal_Putty_IN is set to 3, the third branch will be executed and the robot is "drawing" a rectangular shape.



This approach can be used as a starting point to implement sequences, which are triggered by an external device / PLC. To get further information of how to setup a connection to the Sawyer, refer to the Connections section as well as to the respective tutorials.