Customer application
The Right Automation for Modular Machines

The standard for automation in machine construction today is still the classic PLC. There are many different options for connecting sensors and actuators to the controller. Most requirements are readily met with the 750 I/O-SYSTEM and 767 SPEEDWAY series. This also applies to the field of specialized machine construction, where modular solutions are required.

Specialized machine construction takes place whenever it is not possible to use standard machines, such as CNC machining centers, in production. Machines are created that frequently perform a great variety of production steps, which are then also combined with measurement and testing technology. Typical examples are joining and mounting steps during assembly of complex products – such as outsourced parts for automobile construction. Specialty machines are always designed and built for a particular task. To allow a certain degree of flexibility and repeatability with such machines, despite their specificity, they are frequently subdivided into individual modules – called “cells” – each of which performs one specialized process. A workpiece conveyor system ensures a smooth automatic progression between the individual cells. This also simplifies integration of any required manual work stations into the sequence.

Automation in mechanical engineering:

Custom Automation Architecture
In the Control Cabinet or Directly on the Machine
Modular Automation for Specialized Machines

Custom Automation Architecture

The major advantage of such a modular concept is that the specialty machine designer can install individual cells in a new, specialized machine with no or very few modifications. The machine operator can also benefit from this. If the product to be manufactured is modified only slightly, it may only be necessary to replace one single cell. The remainder of the specialty machine can continue to be used in unchanged form. However, this advantage arises only when the entire automation technology and installation are also highly modular. In a typical application, a central controller coordinates the various cells and transport of the workpieces. Each individual cell has an additional controller, which independently automates the entire task. In the typical architecture of such automation solutions, a PLC is responsible for each individual cell. The modular I/O-System 750 from WAGO, with which the fieldbus coupler establishes the connection to the PLC via PROFINET, can link to the sensors and actuators. The fieldbus coupler forms the head of the I/O-System node, which can be equipped on a custom basis with the individual I/O modules for input and output. Users can select from more than 500 different bus modules to meet the specific requirements – this ensures that the proper I/O module is available for practically any signal. The portfolio ranges from single digital and analog I/O modules to bus modules for specific applications.

An example for this is a bus module for IO-Link, which allows direct connection of the corresponding components. A typical application in specialty machine construction is, for example, use of a gripper on a robotic arm in one machine cell. Control of such a gripper usually requires numerous lines for actuators, position encoders and sensors, which are very difficult to route through a robotic arm. In contrast, control via IO-Link requires only a single line. WAGO’s I/O-System also offers a suitable solution for safety applications. Components in specialty machines that are relevant to safety, such as safety doors, emergency shut-off switches, light curtains and other functions, must be linked to a safety controller using suitable inputs and outputs. For this purpose, the WAGO 750 Series I/O System has safe digital input modules which communicate with a safety controller via PROFIsafe. This also allows conventional I/O modules and safe I/O modules for safety functions to be simultaneously operated in one node.

In the Control Cabinet or Directly on the Machine

However, the WAGO 750 Series I/O System is not merely distinguished by its comprehensive functionality or the variety of signals that can be connected. The system also offers specialized machine builder many advantages, both in the electrical design and during wiring. First, WAGO’s I/O system is very compact, requiring very little space in the control cabinet. The increasing use of electrical drive equipment in machine construction has resulted in a corresponding increase in the number of components inside the control cabinet. This makes saving space vital for nearly all applications. After installing components in the control cabinet, it is necessary to wire them. The WAGO 750 Series I/O System also offers advantages here. Using CAGE CLAMP^® technology allows the wiring in the control cabinet to be carried out straightforwardly, despite the space limitations. To open the spring clamp, it is necessary to insert an operating tool into the corresponding opening. The clamping unit remains open, and the conductor can be inserted until it hits the backstop. The tool is pulled back out of the operating slot, the clamp closes, which ensures reliable contacting.

In the event that sensors and actuators are connected directly on the machine rather than in the control cabinet, WAGO also offers appropriate solutions. The 767 Series SPEEDWAY is a modular, machine-mountable I/O system with a high protection type (IP67) for connection outside the control cabinet. The various modules are simply connected to one another using a system bus, and from there to the central controller via a fieldbus coupler. This solution is particularly interesting for specialized machine builder if parts of a cell are outsourced. A typical example of this is a feed device. If this is completely equipped with SPEEDWAY modules, then only a system bus cable, as well as the electrical power supply and, if necessary, compressed air, needs to be connected to the actual cell in the specialized machine.

Modular Automation for Specialized Machines

For optimal implementation of a modular concept in specialty machine construction, the automation should be based on a modular design. The WAGO 750 Series I/O System and 767 Series SPEEDWAY offer specialty machine builders the perfect tools for this purpose. The variety of possible input and output signals and the possibility of combining standard inputs and safety-relevant inputs in one system offers system engineers tremendous flexibility.

By Jürgen Pfeifer | 2016-10-10