Safety controller simplifies laser cells

A Pilz Automation Technology product story

Edited by the Engineeringtalk editorial team Dec 16, 2003

Trumpf Systemtechnik is using the PNOZmulti to monitor safety functions on a total of four Lasercell 1005 laser cutting machines that are being manufactured for an automotive manufacturer.

Trumpf Systemtechnik in Ditzingen has used the PNOZmulti to monitor safety functions on a total of four Lasercell 1005 laser cutting machines that are being manufactured to meet an order from an automotive manufacturer.

The safety functions were configured with PNOZmulti in order to save wiring and to make the machine controls simpler and more flexible.

The Trumpf Lasercell 1005 is a modular processing station for laser cutting and welding flat, rotationally symmetrical and three-dimensional workpieces.

Customised handling equipment and clamping technology is used in order to process hydroformed workpieces.

The laser cuts a wide range of holes and contours into the hydroformed twin parts, which are more than four metres in length and are separated into left and right frame parts before unloading.

The four laser cutting stations are fully automatic; the hydroformed parts are loaded and unloaded by conveyor and robot handling systems.

During this process some of the personal safety devices are inactive, as the entire area is surrounded by a safety fence.

However, in setup mode it is also possible to work with each of the machines independently, in which case all safety devices must be activated.

In the past the machines' safety functions were monitored using conventional safety relays.

To do this it was necessary to wire up all the logic connections.

The objective in using PNOZmulti was to enable additions and modifications to be incorporated more quickly and with little effort, particularly during installation and commissioning.

Key factors in the decision to use PNOZmulti were the modular design and the simple operation of the graphics configuration tool.

The modular structure provides for a rapid, flexible response to any additional customer requirements.

With the PNOZmulti Configurator it is possible to implement changes quickly, without getting involved with the complex software within the machine controller.

This saves time as well as engineering costs, as there is no need to bring in specialists.

The PNOZm1p base unit evaluates all the safety functions in conjunction with the PNOZmi1p and PNOZmo1p input and output expansion modules.

In addition to the classic functions such as emergency stop or safety gate monitoring, the PNOZmulti also monitors the limit switches on six of the seven axes plus all the laser safety functions.

The logic connections were implemented entirely through software, reducing external wiring to a minimum.

Furthermore, the use of test pulse outputs also increased the level of safety in comparison with the conventional solution.

Two PNOZmc1p signal modules are used to communicate with the standard controller.

This means that the switch status of all the connected sensors can easily be signalled directly to the master machine controller without any additional wiring.

As this project was simple to manage and was implemented without any problems, the company has already decided to use the PNOZmulti as the standard safety controller for a new series of 3D laser cutting machines.