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| Accurate dimensioning of machines and systems with Safety Integrated | | Economical Safety | Ensuring safety in automatic processes is not only a question of human obligation but also of economic reason. According to this principle of Werner von Siemens, Siemens Safety Integrated offers comprehensive systems for the production and process industry which can be combined with optimum services for all phases of the life of a safety system or machine.
The prime concern in the event of machine and system accidents is to prevent injury to persons. But technical failures can also have serious consequences due to production standstills. If a serious incident reveals that the pertinent regulations have not been complied with, expensive claims for damage compensation may result. Machine manufacturers and system installers are required by law to ensure the safety of workplaces. The so called Machine Directive and the appropriate CE mark must be satisfied according to the basic work safety regulations of the EU, thus documenting that the manufacturer of a machine has complied with all the pertinent regulations and specifications in free traffic of goods. This may take place in different ways: by acceptance of the machine by a test body or by certification that the safety requirements of the machine directive or the harmonized safety standard are met.
Functional safety minimizes the risk
The EN 62061 standard "Safety of machinery - Functional safety of safety-related electrical, electronic and programmable electronic control systems for machinery" introduced in 2005 requires an exact calculation of the failure rates for all electronic components relevant to the safety. The standard considers the entire safety chain from the sensor to the actuator. In order to achieve the highest safety integrity level SIL 3, the entire safety function must meet the defined requirements.
The EN ISO 13849-1 standard revised at the end of 2006 (as a successor to EN 954-1) contains requirements for the development, testing and certification of safety-related parts of controls. It also deals with the complete safety functions with all components or devices involved in their execution. So-called performance levels (PL), e.g. on the basis of planned architectures, must be specified for the intended duration of use of safety-related parts of controls.
A safety plan is created in accordance with EN 62061 in order to implement all these safety-relevant requirements for the design and safe operation of a machine. It accompanies the designer of a control function through all phases and is the prerequisite for a verification and validation of the safety requirements. If this is successful, compliance with the basic safety requirements as a basis for the CE mark is satisfied.
Consistent products for all safety tasks
The required safety of systems and machines can be achieved with the failsafe components from Siemens which comply with all the safety-relevant standards. Whether it is a matter of acquisition, commanding and signaling, evaluating or responding, the Safety Integrated product portfolio covers all the safety tasks in the production industry. With this, machine manufacturers and operators get a safety technology that is tailor-made to meet their requirements, which is neither overdimensioned nor underdimensioned and therefore ensures maximum safety at lowest possible costs. The signals are picked up by safety sensors such as light curtains, laser scanners, position switches or emergency stop command devices. Evaluation is carried out in the cell level by 3TK28 switchgear or communication solutions with Profisafe via failsafe Simatic ET 200S F-CPU, S7-300F and S7-400F controllers as well as the failsafe ET 200 periphery. The Simatic ET 200S FC or ET 200pro FC and Sinamics G120/G120 D frequency converters ensure reliable safety functions in the drives.
The safety functions of the Sinamics S120 motion control drive system also provide integrated safety technology for high performance and highly dynamic applications. The Sinumerik 840D CNC is also available with Sinumerik Safety Integrated for machine tool applications.
New products for safe acquisition, ...
Siemens' portfolio contains a number of new products with integrated safety which offer even more possibilities for safe automation. The DP/AS-i F-Link is an absolute world's first. It forms the network transition between Profibus (DP-slave) and AS-Interface and establishes an optimum connection between ASIsafe and Profisafe for the first time. The new ASIsafe K45F 4F-DI compact module has twice as many inputs in the same housing as its predecessor. As a result, two devices can be connected for Cat. 4/SIL 3, thus saving costs and space in the system. Devices can be wired easily and quickly with the new standard position switches of the Sirius 3SE5 series. Individual modules can also be combined in a complete device and the drive head changed easily. The new 3SE5 generation of position switches is available in all variants with integrated ASIsafe electronics. This enables a space-saving installation of the devices in the system.
The 3SF7844 light curtains with integrated Profisafe connecting unit are available for failsafe communication. The Profisafe connection allows full diagnostics via Profibus and independent parameterization reduces downtimes after changing a device.
... reliable evaluation ...
With the CPU 319F-3 of the Simatic S7-300 series and the EM 4 F-DI/3 F-DO input and output module of the ET 200S I/O system, two new failsafe devices for production automation have been added to the portfolio. The new CPU is designed for high performance applications with safety-relevant functions, for example in press and plant construction. The device has integrated Profibus and Profinet interfaces and can take over the standard and failsafe communication between the bus systems via Profisafe as a proxy. The digital, failsafe ET 200S input and output module is tailored to the requirements of SIL 2/Cat. 3 and meets the demands for standard applications in production machines and machine tools. The new ET 200pro FC converter offers the possibility of combining the converter with the freely scalable PLC functionality of the ET 200pro station and installing it directly in IP65. It was integrated smoothly into the ET 200pro system and therefore allows fast module exchange and consistent diagnostics for example. Siemens now also has a wireless control unit with safety functions: the 277F IWLAN Simatic Mobile Panel has two tuning buttons and an emergency stop button. The use with the safety function is tested and certified in accordance with SIL3.
... and fast response
The Sinamics S120 drive system also gets additional safety functions with the new version 2.5. These support the simple, standard-conformant implementation of innovative safety concepts. The extended safety functions Safe Stop 2, Safe Operating Stop, Safety-Limited Speed and Safe Speed Monitor supplement the previously integrated basic functions in terms of safety. They enable reliable monitoring of the drive during operation or when exceptional situations such as setup or maintenance work occur temporarily.
Sinamics G120D adds a distributed version with IP 65 type of protection to the frequency converter series. The converter is particularly suitable for a large number of conveyor technology applications in the automotive industry for example. The integrated safety functions have no encoders and serve to protect man and machine at the same time as saving space, wiring and additional components. All Safety Integrated products are based on standard components and can easily be integrated into the standard automation. This makes it an economical solution for the machine manufacturer and plant operator. The former can therefore react quickly to customer requirements and the latter can equip their machines with the latest state of safety technology.
Safe communication by standard components
The Profisafe safety profile based on Profibus and Profinet is one of the open solutions in safety-oriented communication via standard field buses. Numerous manufacturers of safety components and end users have participated in creating this standard. Profisafe was the first communication standard according to IEC 61508 which allowed standard and safety-oriented communication on one and the same bus cable.
The main advantage of Profisafe is the simple retrofitting, because existing solutions can be extended without having to alter the wiring. Profisafe uses the Profibus and Profinet services for safety-oriented communication. Profisafe deals with possible errors during transmission with a consecutive numbering of the data, time and authenticity monitoring and optimized CRC (Cyclic Redundancy Check) security. Profibus and Profinet together with Profisafe meet maximum requirements up to category 4 according to EN 954-1 and SIL 3 according to IEC 61508 and are therefore ideal for use in the production and process industry.
ASIsafe is the safety-oriented version of the AS-Interface actuator-sensor communication system. It can be used to help link failsafe components such as devices for emergency stop, safety position switches, light grids and curtains as well as laser scanners to AS-Interface. As for standard components, this integration takes place via the yellow AS-Interface cable. Safe users are installed and operated mixed with standard I/O modules in one and the same network. The infrastructure of the network with AS-Interface master, power supply unit and profile cable remains unaffected.
The right service for every user
Safety Integrated not only includes products and systems all to do with safety technology but also an extensive range of services, maintenance and support. Siemens supports its customers with specific measures throughout the machine's life cycle. The customer can be sure of quick service when the machine is in operation. The worldwide local presence of the service teams ensures prompt support and fast spare parts deliveries avoid unnecessary binding of capital. A comprehensive training program on Safety Integrated is also available to the user in the international Sitrain training portal. The latest safety measures can be optimally implemented in this way.
User statement on Sinamics G120
"As a system integrator we are obliged to maintain state-of-the-art technology. We therefore chose a Siemens drive for an application for a rotor shaft manufacturer for bore holes in Singapore.
The plant was due to change over to robot technology. A large spindle had to be moved but the motor retained for constructional reasons. A 6 meter long shaft moulding bench was processed. The functions which can only be performed with the robot are mastered in this technology by the drive solution. The converter-motor combination is triggered by an analog signal from the robot.
The unique safety functions of the Sinamics G120 in its class made it first choice as a frequency converter. The availability of the Safe Stop 1 safety function was decisive. That means the motor stops reliably when the emergency stop button is pressed or when the robot is not running. Another positive effect for us was the possibility of being able to assemble the right modules specifically."
Services: overview
Sitrain
Sitrain is the practically based training center for solving all automation problems. Participants on the Sitrain courses learn all there is to know about the structure of safety solutions.
Solution Partner Automation
Siemens relies on qualified partner companies to meet the growing demands in the field of safety technology. The "Siemens Solution Partners Automation" offer consulting and support for all the relevant safety aspects of automation projects.
Service and Logistics
Siemens also offers international service and a full range of logistics services in addition to specialized personnel for all applications.
Advance 3 / 2007 | |
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