Plant-wide mobile operator control and monitoring reduces plant costs and increases flexibility and availability
09/08/2011 Siemens Industry Automation & Drive Technologies
Mobile operator control and monitoring contributes significantly to reductions in total cost of ownership (TCO). The flexibility and compliance with stringent safety standards permit efficient commissioning and maintenance of plants or machine parts. Wireless mobile panels are the best alternative for this purpose: they provide a high level of safety and allow for additional potential applications thanks to new functions, such as Rapid Roaming.In the fields of manufacturing, logistics, and machine manufacturing, the ability to work flexibly with mobile operator control stations directly at any given plant location is indispensible. For maintenance and commissioning work in particular, customers expect this flexibility while at the same time placing stringent requirements on safety. A mobile panel allows the operator to go to the direct vicinity of the machine and perform critical adjustment operations. In this process, the portable operator control device allows the operator to view the relevant machine part and to simultaneously carry out operator input on the HMI device (human machine interface) without losing eye contact with the machine. To ensure protection of the operator in the hazardous area of the machine, mobile operator control devices must comply with stringent safety standards.
Innovations of proven technology
Wired mobile panels have been available for this purpose for some time. However, the advantages of these mobile operator control devices are limited or hindered by the connecting cable. On the one hand, sections of the plant that are farther away cannot be reached due to the limited cable length and, on the other hand, a long connecting cable (up to 25 meters) hinders handling of the device.
The advantages of mobile operator control devices were fully realized for the first time with wireless mobile panels. These devices deliver the required flexibility, since even plants that cover larger areas with multiple access points can be operated safely and without interruption thanks to Rapid Roaming via iPCF-MC. The handling of the wireless device, which no longer includes switching to other connection boxes,becomes much easier, and the required safety functions, such as the emergency stop and acknowledgment buttons, are available immediately after logging on via the panel. The plant location where the panel is used at a given time is detected automatically by a transponder using an RFID signal. The transponders can also be used in the plant without need for wiring.
Siemens has been offering various versions of Simatic Mobile Panels for some time now. This portfolio is now supplemented by the wireless Mobile Panel 277F IWLAN with integrated safety technology that conforms to Safety Integrity Level 3 (SIL 3 according to IEC 61508) and Performance Level e (Pl e and Cat. 4 according to DIN EN ISO 13849-1) and that can be used even in plants that cover larger areas. The device has a 7.5" TFT display with 64k color depth and a resolution of 640 x 480 pixels. Operator input can be made with touch as well as with keys, which can be configured as direct keys with fast response time for setup mode. Additional operator controls, such as a key-operated switch, illuminated push-buttons, or hand wheels, can be ordered separately. The device is fully suitable for industrial use, has a fall height of over 1 meter, and features IP65 degree of protection. Because it has two acknowledgement keys, it can be operated in safety-related acknowledgement mode by both right-handed and left-handed operators. It is possible to change the high-performance batteries without interruptions (hot swap mode). The device can therefore be used around the clock. While the battery is being changed, the internal backup supply allows communication to continue between the panel and plant and the HMI application to keep running on the mobile panel. A separate charging station is available for charging the device and the replacement battery. A comprehensive set of certificates and radio equipment approvals allows the device to be used practically anywhere in the world.
Configuration of HMI, safety, and convenience functions
The device is configured using WinCC flexible, the standard configuration tool of Siemens for all Simatic panels. Working with this device is easy, thanks to numerous convenience and safety functions. For example, it is possible to set up features, ranging from automatic screen selection/deselection on entry and exit of an operator control area, safety zones, and associated operator control authorizations to safety-related operator control functions with acknowledgement button. If the operator exits the safety area unintentionally, he is notified of this by a dialog message and vibration alarm. Global interconnection of the emergency stop function for the plant is possible in order to ensure fast switch-off using the red-yellow emergency stop button on the mobile panel itself in the event of a dangerous situation. The mobile panel satisfies the safety standards defined for SIL 3 and Pl e and is ce rtified by the Southern German Technical Inspectorate (TÃœV Süd).
High flexibility through Rapid Roaming
The wireless device can also be used in plants that cover a large area and have multiple access points. If the quality of the connection to the currently connected access point becomes worse than that to another access point coming into range, the WLAN communication switches over without interruption to the new access point using Rapid Roaming (iPCF-MC protocol developed specifically for this purpose). This transition occurs so quickly that even safety-critical signals, such as emergency stop, acknowledgement button, and direct key signals, are switched over free of interruption. The mobile panels are easily integrated into the WLAN infrastructure offered by Siemens, e.g., Scalance access points W-700. This enables configuration of WLAN networks based on PROFINET and PROFIsafe (PROFINET profile for safety functionality), including 2.4 GHz networks as well as 5 GHz networks designed specifically fo r industrial environments. Since Scalance access points have integrated the iPCF-MC protocol, they also support the Rapid Roaming function. The 5 GHz range is ideally suited for industrial applications, because there is interference from the 2.4 GHz Office WLAN or Bluetooth devices in this case. The Sinema E program is available for reliable RF field planning. This program enables simulation of the field strength in the plant.
Mobile HMI for applications with and without safety requirements
The safety functions triggered by the red-yellow emergency stop button and the 2-channel acknowledgement buttons are communicated to the connected F-controller via WLAN using the PROFIsafe protocol, and evaluated there. Transponders are available for precise detection of the operator's location. The panel and the F-CPU use the RFID radio signal of the transponders to detect whether a safety-related operator input is allowed to be carried out with acknowledgement buttons in this area. In applications with alternative safety equipment, e.g., robot cells with fences, pressure-sensitive mats, or light arrays, a second variant of the Mobile Panel 277F IWLAN can be used: the RFID tag device. With this device variant, a Moby-D card (Moby D is an RFID system of Siemens) is used to perform location detection for the F-controller when logging on for safety-related operator input with acknowledgement buttons . No transponders are required for this locating action. This safety device also fulfills the safety requirements for SIL 3 and PL e. For applications without safety functions, the mobile panel is also available in a non-safety variant with identical HMI functions. Only the emergency stop and acknowledgement button functions are not available with this variant.
Integrated portfolio
The Mobile Panel 277F IWLAN represents another important expansion of the Siemens portfolio of mobile operator control devices in the form of a device with maximum flexibility and outstanding ergonomics that complies with the strict safety requirements of the German Technical Inspectorate (TÃœV). Compared to conventional mobile panels, this device enables faster commissioning, more efficient plant operation, and reduced downtimes. It fits seamlessly into operator control and monitoring systems, F-controllers, the WLAN infrastructure of known Simatic products, and the software landscape of Totally Integrated Automation (TIA). It is characterized by important, unique features, such as the ability to perform wireless safety-related operator control and interruption-free switchover between multiple access points covering extensive plants.
You can find more information on the Internet at: http://www.siemens.com/industrial-communication
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