I enjoy working with editors from the trade press – contributing to whatever topic they’re writing about. Of course, they have limited space in which to present their topic and they have to include viewpoints from multiple sources. Having neither of those restrictions here let me provide some additional background to a recent article by Dan Hebert for Industrial Networking: Industrial Ethernet Cruises Powerfully Along (titled “Go with What Works” in the print version).
Dan quoted me toward the end of the article: “If devices are available with industrial Ethernet connections, use them. Industrial Ethernets are faster, have greater bandwidth, unlimited node counts, improved diagnostics, easier upward integration, can use standard wireless, and have more topology options.”
Let me expand on the quote with some details on each of those superlatives:
>>Faster: An experiment we report on with 60 nodes shows PROFIBUS at up to 23 millisecond updates (at 12 Megabits/second) vs. PROFINET at one-millisecond updates (at 100 Megabits/second).
>>Bandwidth: Bandwidth is greater because PROFINET is provider/consumer vs. PROFIBUS master/slave and because of the faster speeds and because the network is collision-free.
>>Unlimited nodes: The PROFINET spec (not sure of the others) has no limits to the number of nodes that can be connected (although individual controllers may be limited by their processor speed and memory).
>>Improved diagnostic: Leveraging IT protocols like Simple Network management Protocol (SNMP) and Link Layer Discovery Protocol (LLDP) provides network diagnostic information.
>>Easier upward integration: The PROFINET spec includes movement of data from plant floor to MES systems. I don’t think any of the others do.
>>Standard wireless: WiFi and Bluetooth can be used to transmit PROFINET data. Wireless Access Points from different vendors can be mixed and matched.
>>More topology options: line, star, rings, and combinations can be used; most lower networks are line only.
Additional capabilities: PROFIenergy provides substantial savings in energy bills. Using names instead of numbers allows PROFINET devices to be replaced without using a computer and without setting switches.