Most of the major manufacturing automation end users and suppliers are using or considering Ethernet as an industrial control option for field devices, drives, power management equipment, and special purpose controllers. Engineers and others who design Ethernet networks for these applications must follow correct installation procedures and must select network equipment that will function in plant environments with little or no downtime.
Power supply configuration, proper network grounding, selection of network topology, and configuration of network switches are critical when Ethernet is used in industrial applications. Design techniques such as port-by-port addressing can significantly reduce the time required to replace field devices by eliminating the need for maintenance personnel to manually input IP addresses.
Cicicom represents the global experts in communication, monitoring and control for industrial automation and networking, Red Lion, who has been delivering innovative solutions to customers for over forty years. Our award-winning technology enables companies worldwide to gain real-time data visibility that drives productivity. Product brands include Red Lion, Sixnet and N-Tron.
Using Ethernet to Create Highly Reliable Wide-Area Security, Access & Monitoring Systems
More and more organizations are safeguarding themselves by adding comprehensive security, surveillance and electronic access systems to their campuses and properties. The proliferation of these systems, on both public and private land, has grown exponentially in recent years. These systems can now be found in office parks, industrial complexes, college campuses, retail centers, public transportation hubs, and other places where security is a high priority.
While the wide-spread availability of security products (cameras, intercoms, access control devices, alarms, control systems, etc.) has fueled growth, they have also complicated installations. Expert planning is essential. The first challenge is to make sure that all devices share a common communication platform. Ethernet is the natural choice. It is a proven communication protocol that provides fast, reliable service. To guarantee maximum reliability, serious consideration must also be given to network topology, appropriate bandwidth and system redundancy.
Campus Security / Wireless Access Applications
The star network configuration is always the most efficient way to design a small security network topology with wireless access. It is a very simple design allowing the use of unmanaged switches in the field tied directly to a central switch with a high-speed backplane. The fiber optic ports in this example can be used to connect to field switches up to 80 KM from the monitoring station. Power over Ethernet (PoE) switches in the field will provide both communications and power to PoE-capable devices via a single CAT5 cable.
The gigabit fiber optic ring ensures electrical isolation between buildings and provides the proper bandwidth to support cameras and wireless access points. The ring topology also provides redundant communication paths in the event of the loss of a fiber link.
System monitoring is accomplished through switches deployed within the ring. These devices use either Rapid Spanning Tree Protocol (RSTP) or a high-speed proprietary ring control protocol like N-TRON's N-Ring (30ms break detect) to send Ethernet heartbeat packets around the ring. The designated ring manager blocks one of the ring ports so that all traffic, with the exception of the heartbeat packet, will be routed through the other port.
This prevents a loop from being formed that would cause continuous recirculation of packets. Unchecked loops will eventually create a network storm ending all communications. Heartbeat packets are allowed to pass through the blocked port and are timed by the ring manager to ensure that the ring is intact. The ring manager detects a break in the system if the heartbeat packets are not received on time. It will open the blocked port in response. This allows communication to continue around the unresponsive link. When the link is restored, the ring resumes normal operations with one blocked port to prevent a loop.
See also Network Solutions