Точки доступа IEEE 802.11n Siemens

Область применения

The access points of the SCALANCE W700 product line are designed for both industrial use and for demanding climatic requirements outdoors. Versions for the inexpensive integration in cabinets or in machines are also available. They provide a reliable wireless link, redundancy mechanisms, and fast handover of nodes from one access point to the next (roaming). This allows processes to be monitored and loss of production due to machine downtimes to be avoided.

Industrial Wireless LAN (IWLAN) can also be used in time-critical applications in factory automation (PROFINET IO) or for safety-related signals (PROFIsafe).

Due to their high degree of protection (up to IP65) and extended temperature range from -40 °C to +70 °C, the access points are ideally suited for use outdoors. SCALANCE W products are silicone-free and can therefore also be used in paint shops.

When using the RCoax cable (radiating cable), operation is particularly reliable in conveyor systems and all track applications (e.g. storage and retrieval systems, suspended monorail).

Application examples:

• Automated guided vehicle systems and suspended monorails;
  prevents wear and offers high flexibility for traffic routing thanks to the wireless transfer of data to the vehicles. It is also possible to transfer PROFIsafe via IWLAN.
• Cranes;
  high flexibility due to access to data communication with the moving unit independent of the location
• Mobile control console;
  reliable intervention in the process thanks to data communication over IWLAN with mobile units (e.g. Mobile Panel 277(F) IWLAN); the number of operator panels is therefore determined by the number of personnel and no longer by the number of control desks.
• Wireless access to field devices for configuration and testing
• Passenger transportation systems;
  transmission in passenger information systems, e.g. high-quality video streams between the control center and buses or trains
• Tunnel application;
  reliable wireless link since the devices can handle multiple path propagation better by using the MIMO technology.
• Communication with moving stations (e.g. mobile controls and devices), container logistics, storage and retrieval machines, conveyor systems, conveyor belts, rotating machines, trucks
• Wireless coupling of communication segments and bridging of large distances for fast commissioning and cost-effective networks in applications where cable routing would be extremely expensive (e.g. on public roads, rivers, lakes, train lines)
• Localization of personnel and machines using WLAN tags and localization software from AeroScout

Обзор

The access points of the SCALANCE W700 product lines are ideally suited for setting up Industrial Wireless LANs (IWLAN) for 2.4 GHz or 5 GHz. They can be used in all applications that require a high degree of operational reliability, even in extremely harsh surroundings.

• High data rates (up to 450 Mbit/s in connection with Channel Bonding) as per IEEE802.11n
• Reliable wireless link by using of MIMO technology (Multiple Input, Multiple Output). For this, SCALANCE W access points use up to three streams for simultaneous sending and receiving.
• SCALANCE W700 Access Points are suitable for any application: for outdoors with high requirements regarding climactic conditions, for installing without a control cabinet indoors, for installing in the control cabinet, and for an extended range of environmental conditions.
• Reliable thanks to a rugged, impact-resistant enclosure, protected from water and dust (up to IP65), resistant to shock, vibration and electromagnetic fields, resistant to condensation thanks to the use of coated PCBs
• Demanding applications with real-time and redundancy requirements, such as PROFINET with PROFIsafe
• Conformant to standards through supporting IEEE802.11; expanded software functions especially for use where increased reliability is required, e.g. cyclic real-time data traffic and very high-speed roaming (iPCF, iPCF-MC)
• Configuration support by means of wizards and online help; easy management via Web server and SNMP
• Configuration and diagnostics using Web based Management, Command Line Interface, and SNMP. Devices and networks can be configured using STEP 7 (TIA Portal). For cyclic monitoring, diagnostics and documentation (reporting) in network mode, the SINEMA Server software is recommended.
• Enabling of further functions using the KEY-PLUG swap medium (iPCF, iPCF-MC, iREF)
• Fast replacement of devices if a fault occurs thanks to use of optional KEY-PLUG/C-PLUG (Configuration Plug) swap medium

Функции

A simple RF field can be established with a single access point (infrastructure mode). The access point provides at least one Industrial Ethernet interface for connection to the wired network. Nodes, such as mobile controllers or a Field PG can move freely within the RF field and exchange data with other nodes via this access point.

If the RF field of a single access point (wireless cell) is insufficient, it can be expanded by further access points. The individual wireless cells must overlap so that moving nodes can be handed over seamlessly from one access point to the next (roaming). This is transparent for the application. The access points must be able to exchange data via Industrial Ethernet or a Wireless Distribution System (WDS).

If the access points are not connected to Industrial Ethernet using a wired connection (e.g. no cable tray available for a data line), the "Wireless Distribution System" mode must be selected. An access point from the SCALANCE W700 product line can communicate via WDS with several other access points that are not connected to the data network by a direct wired connection. Remote directional antennas can be used to achieve ranges of several thousand meters outdoors.

Apart from a reliable radio link, the SCALANCE W700 Access Points are characterized by their support of IT mechanisms:

• IEEE 802.11a/b/g/n for different frequency ranges
• IEEE 802.11e for Wireless Multimedia (WMM)
• IEEE 802.11i for security
• Construction of redundant networks with the Spanning Tree Protocols (RSTP, MSTP)
• Virtual networks (VLAN) for example to logically separate different user groups
• Sending the log entries of the SCALANCE W devices to a Syslog server
• Modern security mechanisms (e.g. network security such as IEEE 802.1x, RADIUS, EAP mechanisms)

Security

A high degree of data security is achieved by means of the WPA2/IEEE 802.11i mechanisms. These define modern procedures that control a regular exchange of the complete 128-bit key as well as performing the access check (authentication) of a node. The Advanced Encryption Standard (AES) is available for data encryption.

On top of this, access to the devices (HTTPS) is encrypted and a secure logon (SSH) is possible. If a security concept in combination with SCALANCE S is required, the security requirements can be increased using Virtual Private Networks (VPN).

iFeatures (only in conjunction with KEY-PLUG)

iPCF (industrial Point Coordination Function):
The iPCF mode is a good choice for applications with requirements for real-time and predictable response times (deterministic response), even when mobile nodes are roaming from one access point to the next. This ensures that wireless PROFINET IO is supported and that safety-related signals, e.g. emergency stop, can be linked into the RF field. This means that even video signals from mobile nodes can be transmitted with a high level of quality. The iPCF mechanism expands the IEEE 802.11 standard and must be available on both the client module and the access point. In an RF field in which iPCF is used, no IEEE 802.11-compliant nodes can be operated.

iPCF is recommended for applications where wireless network nodes move along predefined paths (e.g. suspended monorail). RCoax radiating cables or directional antennas must be used for this purpose.

Linking in an automated guided vehicle system using iPCF with the SCALANCE W774-1 RJ45 and KEY-PLUG

iPCF-MC (iPCF Management Channel) ¹⁾:
iPCF-MC is available as a further development of iPCF. This mode should be used if IWLAN stations that also support iPCF-MC move freely about in the coverage area (especially when using omni-directional antennas) and are to exchange data deterministically. This functionality can only be achieved in connection with access points with two wireless interfaces and the KEY PLUG.

iREF (industrial Range Extension Function):
The range of an individual access point is very important, e.g. for path-based applications. Using iREF, it is now possible to align the various antennas of a wireless interface in different directions. This allows a longer path or a greater area to be covered using a single access point, which reduces the number of channels used and the number of access points.

Note:
These iFeatures cannot be used in parallel.

Diagnostics and management

• Web-based (HTTP/HTTPS) management tool for configuration and diagnostics using a standard browser
• LEDs for signaling operating status and fault/error states
• Signaling of faults by means of SNMP trap or e-mail to a network management tool
• Configuration and diagnostics using Web based Management, Command Line Interface, and SNMP. Devices and networks can be configured using STEP 7 (TIA Portal). For cyclic monitoring, diagnostics and documentation (reporting) in network mode, the SINEMA Server software is recommended.

¹⁾ Available soon

Особенности

• Predictable data traffic (deterministic response) and defined response times on the wireless link
• Reliable wireless link, e.g. by using MIMO technology and monitoring the wireless link
• Cost savings by having only one wireless network both for process-critical data and for non-critical communication
• Future-proof because all products are compatible with the internationally recognized WLAN standard IEEE 802.11n, suitable for license-free 2.4 GHz and 5 GHz frequency bands (ISM bands)
• Implementation of data-intensive applications such as video streaming
• Reduced operating costs, because there is no wear and tear on rotating and moving plant sections
• Cost-effective connection to devices which are remote, difficult to access or installed in hostile environments
• Investment protection because flexible feature expansions (iFeatures) are possible by using the KEY-PLUG