by Mark Knebusch, Softing Inc.
As more devices are connected through networks, the reliability of these networks is critical. One way to guarantee reliability is through testing and monitoring. Here are tips to ensure you pick the right tools to secure network reliability.
As data flows faster, a solid wiring foundation in industrial Ethernet applications is needed to keep communications among devices working smoothly. More devices are connected every day with larger bandwidth needs. The resulting higher transmission speeds mean that proper cable setup, testing and monitoring are an integral part of keeping a network running. To ensure your business achieves and maintains a competitive advantage, cable selection and network monitoring should be an important consideration for every application.
Whether you’re installing a new system or upgrading an old one, the first step after installation is to test the media. Once it is tested, and in some cases formally certified, you can connect electronics. Also consider using a permanent monitoring system to observe each device connected to the network.
Ongoing testing and monitoring of the network eliminates a host of problems and costs associated with industrial Ethernet applications.
Industrial protocol integration
Ethernet is the largest and most widely used network. As new Ethernet technologies matured and advanced, organizations such as the TIA, ISO and IEC developed standard wiring, cabling and installation specifications.
In many plants and facilities, standard TCP/IP and industrial protocols based on Ethernet coexist. PROFINET, Ethernet/IP and Modbus TCP/IP add capabilities for factory automation that have extended the reach of Ethernet. While each protocol is associated with a major vendor, all are supported by multiple vendors.
Dozens (sometimes hundreds) of devices are connected on a given network. While devices often can be monitored individually to check their status, production and facility operators often seek a solution that allows overall monitoring of entire networks through a single interface.
The importance of cable selection
A number of factors are important to cable selection, including intended use, longevity and speed. In addition, consider the following when selecting the type of cable needed:
• Cat 5e is in a large number of current industrial installations and offers up to 100 MHz of bandwidth at speeds up to 1 Gb/sec.
• Cat 6 cables offer 10 Gb speed and a bandwidth of 250 MHz.
• Cat 6A offers 10 Gb/sec speed and bandwidth of 500 MHz due to much lower crosstalk.
• Cat 8 is emerging for data center/server farm applications with 40 Gb/sec and the likelihood for 2 GHz bandwidth.
Additional factors include cost, reliability and inventory availability.
Regardless of the cables you use for your application, it is important that you not mix cable types. If upgrading a system, be sure to select a single cable type that fits your needs and use it for the entire installation, as mixing and matching cables may degrade network performance.
Because cabling is usually not replaced as often as other components and hardware like PCs and servers, chose cabling that will accommodate changes in industry standards. For example, with the increased demand on networks—now and in the future—faster and faster speeds are required, as evidenced by the evolution of the TIA 568 cabling standards.
As network frequencies increase, impedance, crosstalk and other parameters become more critical. While Cat 5e is currently common, increasingly Cat 6 and 6A are being installed in industrial applications. Cat 8 cable, which will be widely used by data center applications, is currently in draft mode and is expected to be finalized as a future standard. Even at the draft mode stage, various Cat8 cabling systems are being sold today.
With more information being sent and received, testing is a necessity in industrial Ethernet applications. Issues arising from incorrect cable installations can cause thousands of dollars or more in lost productivity if the system fails or malfunctions.
When it comes to testing and certifying Ethernet cables, testing devices with pass/fail test results speed up the process. Testing many types of cables according to different standards is also a plus in facilities that use a variety of protocols and cables. Additional graphical data on frequency range performance can ensure successful operation under a range of conditions.
The value of network monitoring
Once the cabling is installed and certified, monitoring network traffic and devices on an ongoing basis is recommended. A monitoring system can deliver a wealth of real-time data that can be captured for performance troubleshooting.
Monitor parameters include cable breaks, traffic, device status, topology and performance analysis. Network monitors not only target the location of the problem, they also offer historical documentation of the system.
Ethernet cabling at all levels in a plant or facility is connected to more devices and transmitting more data than ever. Plants and facilities are more dependent on their networks as the amount of data and its value increases. Thus, cabling needs to be tested before devices are connected and the protocols need to be monitored once the networks are active. This places a heavy importance on the tools you pick to ensure the reliability of your industrial network—from cable certifiers to monitoring software—so make sure to choose wisely.