Many engineering companies and control experts have worked for years to develop easier, faster, more sophisticated ways of programming control systems-for applications as diverse as process management or materials handling. Beck IPC GmbH, part of the Festo group (Hauppauge, NY), believes it has come up with such a system which it has called, appropriately enough, Easy Control. The simple software, designed to run on a Palm Pilot, was demonstrated at the SPS IPC Drives show (Nuremburg, Germany) in December 2000.
Says Bernhard Plagemann, customer relations manager and an engineer at Beck IPC, "Easy Control is not a control system itself, it's more comparable to a programming language. It is easier and faster to program than conventional controllers. Because standard handling device combinations are stored as pre-configured information, less time is needed for configuration, and no specialist programming skills are necessary. It is also possible to run Easy Control on a cheap, small programming device, such as a Palmtop computer."
Easy Control is based on Festo's own software FST (Festo Software Tool), which complies with the standard IEC 61131-3, the only global standard for industrial control programming. Plagemann notes the justification for developing Easy Control lies in the continuing rise in the cost of control software compared to the hardware. "Programming generally is still tied to experts in automation, and simple, small devices still need far too many preparation and configuration tools than the application really justifies," he says.
Palm has offered a stable environment for software development for at least the past three years, and the Palm-based development should save many hours in programming time.
The idea behind Easy Control is that the action of a standard handling device consists of a combination of straightforward axes, typically termed x, y, z for the linear movements. Rotating movements are denoted by R, gripping actions by G. Assuming that these axes have no more than two or three end positions, Easy Control can define the movement of the axes with simple signs programmed directly into the Palm Pilot. For example, the instruction X+ will initiate movement in the forward direction; X- moves backwards; Xm moves to the median point; G+ closes the gripper, and so on.
The developers also feel strongly that the technician should have a tool which allows him to configure the sequence of steps independently-hence the choice of a Palm Top device, which can easily be carried around a plant or factory.
Easy Control software contains four key stages to start up a given system or device: configure, test, teach, and run. Configuration allows the definition of movement axes, limit switches, start and stop inputs, and error and ready outputs, among other functions. In test mode, the axes can be moved while in "online" mode. Also, the sensors and actuators can be tested. In teach mode, the sequence of these movements is stored in the controller, which can be a simple PLC. Run mode allows editing of the step sequence.
In developing the Easy Control solution, Festo supplied the hardware and the know-how about handling the (pneumatic) drives. Beck then developed the control system, and together the partners developed version 1.0 of the software. Version 2.0 will be out before the end of the year.
Plagemann adds, "With the Palm system, it is possible to program a sequence of 50 steps. We want to develop some software for automation, for preventative maintenance, for motion systems, and for control applications. We believe we are the first to develop such applications on the Palm platform."
Festo and Beck are convinced that simple hand held computers like the Palm are ideal to configure simple automation devices. The package is not yet on the Windows CE platform although Plagemann says the partners are looking at that possibility, anticipating that the CE platform will take off in industrial control and monitoring applications. The next step is likely to be a Bluetooth version with a radio frequency connection.
Parameters of the IEC 61131 standard
Standard IEC 61131 was established to standardize the multiple languages, sets of instructions, and different concepts existing in the field of automation systems. The great variety of PLC concepts has led to an incompatibility between the different PLC platforms and manufacturers. IEC 61131 standardizes the programming languages, the interfaces between PLC and programming system, the sets of instructions, and the handling and structuring of projects. Advantages of using IEC 61131-conforming PLCs and programming systems are the portability of all platforms, and the use of modular programming concepts, reducing costs and programming steps for automation systems.
Remote control by mobile phone
A transparent cabinet is packed with multicolored chocolate bars. The sight has already pulled in a large crowd, even though nothing appears to be moving. Beside this 6-ft tower of temptation is an unassuming notice that reads "Dial this number for a surprise." I dial the number, whereupon a system of actuators and conveyors springs to life to deliver me a bar of orange flavored chocolate. Around me dozens of people reach as one for their mobiles and start pounding on their keypads, visibly salivating.
Together, Festo and its subsidiary Beck, devised this eye-catching display at Nuremburg's SPS/IPC Drives show to demonstrate the GSM capability of Beck IPC's FEC FC38 controller. The new controller contains Beck IPC-developed software which allows the creation of texts (SMS messages) and the interpretation of incoming texts.
With FEC FC38, it is now possible for control systems to send an SMS determined by an event in the process, such as error, production ready, or waiting for material. Alternatively, it can receive an SMS depending on the interest of an operator. Examples would be status of production, or error number.
Beck IPC's combination of a control system with a mobile phone, and a GSM modem, supersedes earlier control systems connected to a local network designed to send an e-mail if the machine failed, as well as other systems connected to a telephone modem for notification by fax.
The FEC FC38 controller-based communication suits a small control system with perhaps 20 I/Os to check for error signals of a given process or to give simple commands to this application. To this set up are added standard communication features, such as serial or Ethernet ports. A GSM modem is incorporated into the controller's housing to allow the sending and receipt of SMS messages.
GSM and SMS
GSM stands for Global System for Mobile Communications, which is an open, non-proprietary system that is constantly evolving. One of its strengths is the international roaming capability. This gives consumers standardized same- number contactability in more than 159 countries. GSM satellite roaming has extended service access to areas where terrestrial coverage is not available.
GSM differs from first-generation wireless systems in that it uses digital technology and time division multiple access transmission methods. Voice is digitally encoded via a unique encoder which emulates the characteristics of human speech. This method of transmission permits a very efficient data rate/information content ratio.
SMS, or Short Message Service, is the ability to send and receive text messages to and from mobile telephones. SMS was created as part of the GSM Phase 1 standard. The first short message, it is believed, was sent in December 1992 from a personal computer (pc) to a mobile phone on the Vodafone GSM network in the UK. Each short message carries up to 160 characters.