In smaller plants, Krüger uses Siemens Simatic S7-1200F fail-safe programmable logic controllers (PLC) while Simatic S7-1500F systems are used in more complex projects.
Andreas Pfeifer, Head of Project Engineering at Krüger, summarizes the benefits of an S7-1200 PLC which is used, for example, to automate the robot cell in a current project with lifting devices and gripper solutions: "It gives us the option of controlling and monitoring all the components in the robot cell independently of the robot programming – in this instance, the end position sensors for querying the gripper position. In addition to this, all the communication between the robot and the welding machine is via a Simatic S7-1200F control using the Profinet ethernet standard."
Safety areas with flexible design
In addition to standard communication, the robot is also connected to the machine on a safety level using the Profisafe communications standard. Using the "Safe Operation" option allows the robot's actions to be limited to certain areas. This also allows the operator to use the control to block or release specific transfer paths either as required or depending on the machine status. This provides flexible safety areas for the robot and operator. All of the safety functions are available in the PLC and are displayed on a Simatic KTP700 Basic Panel. "This allows the customer to quickly diagnose faults all the way down to the channel fault," says Pfeifer.
Convinced in every respect
The engineering is completed in the TIA (Totally Integrated Automation) engineering framework portal. As the system is automated from end to end, the programmer does not have to switch between different software solutions and programming languages which saves time and effort. A Simatic ET 200SP I/O module also contributes to this by rationalizing and simplifying the wiring. Krüger's previous positive experience with Simatic S7-1200 systems means the company intends to use other functionalities of the fail-safe control in the future, for example, remote access through the webserver function. "This will enable us or the customer to do initial diagnostics from home or on the road using a computer or mobile phone," says Pfeifer.