Keeping automation networks running efficiently has become one of the most important requirements for maintaining an efficient industrial automation system. Thankfully, the managers entrusted with this critical task can turn to a number of diagnostic tools that can help them find ways to fine tune networks for more efficiency or fix problems when they inevitably arise.
The shift to Ethernet has dramatically expanded the size of many industrial networks, and it’s also brought significant speed increases, so there’s far more traffic moving across the twisted pair wires. In factories where network downtime can cause big problems like lost production, keeping these networks running nonstop is far more important than in office environments where brief outages are almost unnoticed.
Industrial networks should be monitored to ensure they’re running at optimal levels. One of the mainstays of any diagnostic program is the managed switch. Managed switches don’t add much to the cost of a network, but they collect a wealth of information that tells managers how the network is running.
“You get real benefits when you use managed switches,” says Tim Pitterling of Siemens Industry Automation Systems. “You can monitor settings, error rates and connections, making it easy to see where you can improve performance.”
There is a broad range of diagnostics software which you can use together with managed switches. Some of these tools are common, off the shelf programs used by many Ethernet users at homes and businesses. Others are designed specifically for the many diverse products and technologies used in industrial applications.
The base for all these tools is the simple network management protocol (SNMP). This protocol provides access to all the diagnostic information gathered in a managed switch.
One important aspect of network diagnostics is to understand which switches are the most active and which ones are being underutilized. By reading out the SNMP information regarding the amount of data running through a switch, related tools can document how often services are available. This can help managers determine whether they’ve got enough capacity to cover when a switch fails.
“With SNMP, managed switches and the right diagnostic tool, you also have better transparency into the behavior of your network,” Pitterling says. “A good diagnostic tool can draw an automated topology to make it easier to see where and which port went down.”
When a port does fail, these tools will pinpoint its location so technicians can go directly to the failed module and replace it. This reduces downtimes significantly.
Good diagnostic tools let users quickly see where problems such as high loads are. Visual data makes it very easy to spot saturation points. Diagnostic software also helps users see where errors occur and how loads are changing over time.
“Monitoring errors on the network brings a lot of benefits. You can see if loads are going up and you can see whether you need to update something on the network. The right diagnostic tool can proactively inform you when certain load levels are exceeded. That helps you to act and avoid saturation,” Pitterling says.
While a number of tools developed for IT applications fit well in industrial environments, that’s not a universal occurrence. Many aren’t designed for the requirements of industrial applications.
“IT teams often try to take over automation networks, but their tools don’t understand things like the Discovery and Configuration Protocol (DCP) used by PROFINET,” Pitterling says. This, combined with a number of other requirements like support form an extremely broad product mix, mean that industrial users also need specialized tools.
Many industrial companies provide tools that are designed for use in automation environments. Given the vast array of equipment that can be operating in even a fairly small facility, these tools must be easy to understand so technicians can get systems up and running again in minutes. The cost of downtime is far higher for a production line than for IT applications where interruptions held to a few minutes can often be overlooked.
Though there’s been a real push to improve user interfaces over the past few years, many diagnostic tools for industrial systems remain hard to use. “Too many tools are not easy to use without a lot of understanding and training,” Pitterling says.
“In industrial applications, you need easy-to-understand diagnostics. This is why we developed SINEMA Server,” Pitterling continued. “Technicians like the possibility to create user maps where they are able to place the network components on a background image that shows the plant floor for very easy diagnostics. When there are maintenance issues, they can direct people exactly where they need to go to get things fixed.”
When diagnostic systems show the end device and also point out which component has failed graphically, maintenance personnel can quickly get to the site with the proper tools and replacement parts. That’s critical given the high cost of downtime.
“In IT environments, five minutes of downtime isn’t usually a huge issue. But five minutes without production means a lot of lost revenue,” Pitterling says.
That’s why industrial applications often use techniques like Media Redundancy Protocol, which provides a switchover time of only 200 milliseconds. MRP is an important tool in many industrial applications, but it represents a challenge for IT teams. Many IT tools don’t understand this high performance protocol, so these tools aren’t much good when IT teams are troubleshooting networks that use MRP.
Though managed switches are needed to gather data analyzed by these tools, it can be an option to use unmanaged switches in areas of the network where diagnostic data is not important. Unmanaged switches don’t have built-in intelligence, so they can’t provide as much functionality, they don’t have IP addresses, nor do they provide the benefits that come with SNMP. However, they can provide additional ports or different media connections, such as fiber.
“You can add unmanaged switches in SINEMA Server to visualize them, but you can’t manage them nor do you get information regarding load or errors. That’s the tradeoff between using an unmanaged switch vs. a managed switch,” Pitterling said.
When systems are configured to maximize the amount of data gathered without incurring extra cost, users will find it easy to keep networks running smoothly. Picking the right diagnostic tools is a key element for those tasked with maintaining network integrity.Have an Inquiry for Siemens about this article? Click Here >>