Introduction
Mice industrial switches
Hiper ring redundancy
RS2 industrial switches
A very important aspect when looking at the total availability of a system with respect to the process control system is the reliability and availability of data transmission from the actual core of the process automation system – the controllers – to where the process data is handled (real-time database - Runtime server) and the operator stations that are responsible for operation and monitoring. In this case, it's necessary to implement redundancies to achieve the highest possible network availability. The loss of a transmission line must be detected in a fraction of a second, with a suitable "detour" in place to make sure that the data gets transferred nonetheless. The necessary structures can be implemented in a ring design to meet these demands. Alongside the topic of redundancy in industrial Ethernet, it also needs to be taken into consideration that, in addition to today's Fast Ethernet standard (100 MBit/s), more and more transmission routes will need to be implemented using Gigabit Ethernet (1000 MBit/s) in the future. To meet this demand, modular switches are already being prepared. Through the use of media modules, the transmission rate and media design can be selected as anything (10 / 100 / 1000 BASE TX, 100 Base FX Multimode FO, 100 BASE FX Singlemode FO, etc.), which provides the highest degree of flexibility when setting up a network for old and new systems alike.
MICE industrial switches
MICE is designed as a modular, managed industrial Ethernet switch for normal Ethernet (10 Mbit/s), Fast Ethernet (100 Mbit/s), and Gigabit Ethernet (1000 Mbit/s). There are three switch types available, where the maximum extension of one switch can be used for up to 28 ports using media modules. The switches are designed as modular devices for mounting on the rail. The switch is based on the "store and forward switching mode" and inherently offers important redundancy functions like HIPER Ring (ring structure), redundant 24 V supply, and diagnostic functions (with message contact). These are necessary for setting up replacement lines or reporting communication interruptions and disturbances. The ring structure (HIPER Ring) can be extended up to 50 switches (the ring switching time is typically < 50 ms when using fiber optic cables). The media modules for MICE switches (MS...) make it possible to combine various media on the network (100/1000BASE-TX, and 100Base-FX Multimode FO, 100BASE-FX Singlemode FO, etc.). A modular switch may be used when implementing structures with Gigabit Ethernet or if there is a demand for grouping together network stations that predominantly use different media, but are otherwise located in relative proximity to one another. MICE switches are managed industrial Ethernet rail switches and are able to provide extensive diagnostic data. It is possible to combine RS2 managed industrial ETHERNET rail switches and MICE managed industrial EHTERNET switches in the same HIPER Ring without additional limitations. This lets you implement a design that uses RS2 and MICE switches to match the exact circumstances of your system.
HIPER ring redundancy
I/Os, controllers, and control computers in a process control system are usually distributed across several locations, with at least one switch in each place. These locations are best connected using fiber optic segments (protection against lightning, electrical isolation, superb EMC qualities, large distances can be bridged). This connection represents the "backbone" of the industrial Ethernet system. When a switch on this backbone fails, two subnets have the problem that they cannot communicate with each other. To prevent this from happening, it's necessary to convert the line structure of the backbone to a ring structure. This means that the first device (switch) and the last device (switch) in the backbone must be connected to each other so that ring structure actually derives from the line structure. If the backbone has been formed into a redundant ring, then the "redundancy manager" function needs to be enabled on exactly one switch. The redundancy manager's job is to permanently check the ring using watchdog packets to detect any interruptions. However, data transmission doesn't take place over the redundant line (fiber optic segment); instead, it is only used for watchdog industrial Ethernet redundancy packets. If these watchdog data packets don't arrive on the 2nd port (2nd side of the backbone), the redundancy manager knows that the ring has been interrupted (at some position). It then begins sending all data packets over the redundant line (fiber optic segment). Once the disturbance has been cleared, the redundancy manager uses its integrated "self-healing" function to automatically reestablish its original behavior within approx. 300 ms. This makes it possible to replace or repair the patch cables or fiber optic cables and reestablish normal HIPER Ring operation without having to deal with software or some kind of DIP switch.
RS2 industrial switches
RS2 switches are available as unmanaged and managed industrial Ethernet rail switches. The switches are designed as compact devices for mounting on the rail. Both Ethernet (10 Mbit/s) and Fast Ethernet (100 Mbit/s) are supported. Devices are also available that have a different number of ports (the maximum number of ports is 16). The switch is based on the "store and forward switching mode" and inherently offers important redundancy functions like HIPER Ring (ring structure), redundant 24 V supply, and diagnostic functions (with message contact), which may be necessary for setting up replacement lines or reporting communication disruptions or disturbances. The ring structure (HIPER Ring) can be extended up to 50 switches (the ring switching time is typically < 500 ms when using fiber optic cables). The different RS2 switch design variants also make it possible to combine various media on the network (10/100BASE-TX and 100Base-FX Multimode FO, 100BASE-FX Singlemode FO). A compact switch may be used if there is a decentralized topology being used. Network stations are primarily connected with 10/100BASE-TX technology. The backbone is usually designed as a fiber optic cable (mono-mode FO, multimode FO) in and through the different locations. RS2 switches provide extensive diagnostic data when using a managed industrial Ethernet rail switch design.
