A relay datasheet says “PRP.” The switch says “PRP.” The SCADA server’s network card says “PRP.” On site, the frames still come through twice, or the supervision counters stay at zero, or a RedBox doesn’t see half the nodes. Often the reason is that “PRP” isn’t one protocol. There are two versions on the wire, and they don’t… Read More: PRP-0 vs PRP-1: What Changed in IEC 62439-3, Edition by… »
Network variables get all the attention in LonWorks. They’re the clean part: bind an output to an input and values flow. But a lot of the traffic on a real channel isn’t network variables. It’s the commissioning tool installing nodes, a gateway tunnelling another protocol, a SCADA master reading status, and nodes answering all of it. That traffic… Read More: LonTalk Explicit Messages and Network Management, Byte by Byte »
Almost every LonWorks page online is about air handlers and lighting. That’s half the story. LON was also a station bus in MV and HV substations. ABB built a whole protection and control range on it: REF 54x feeder terminals, REC and REM units, SPACOM relays behind gateways, and MicroSCADA on top. Those systems are still in service.… Read More: LonWorks in Substations: LON Bus for Protection and Control »
SCADA does not “read the PLC.” It reads specific memory locations inside the PLC, over a network, using a protocol both sides agree on, on a schedule the SCADA engine controls. Every screen value, every alarm, every trend point comes from that one loop: ask, answer, map, display. Most explanations stop at a list of protocol names. That… Read More: How Does SCADA Communicate With a PLC? Explained Simply »
Putting LonWorks on an IP network sounds like the easy part. The protocol doesn’t change, and Ethernet is already in the building. Then a device stops forwarding and nothing in the LonWorks tooling explains why. ISO/IEC 14908-4 doesn’t rewrite LonTalk into a different application protocol. It transports LonTalk packets over IP using a mechanism it calls CNP/IP. But… Read More: LonTalk over IP (IP-852): Setup and Troubleshooting »
The first thing to understand about transparent mode is that there is no fixed control word bit layout to memorize. The information is not hidden. Under ABB Drives or PROFIdrive, the profile defines how the control word, status word, references and actual values are interpreted. Under Transparent 16 or Transparent 32, the FPBA-01 does not impose that interpretation.… Read More: ACS880 PROFIBUS Transparent Mode: Control and Status Words »
Two profiles. The same drive can use either one over the same network. Even when the configured process-data size is identical, the meaning of the words can change. That is what makes this comparison worth writing down. Nothing visibly breaks when you pick the wrong one. The bus goes green, the PLC exchanges data, the drive accepts a… Read More: PROFIdrive vs ABB Drives Profile: Key Differences »
One parameter decides how your PLC talks to an ACS880 over PROFIBUS. It is 51.05 Profile. Not 51.02. That one is the node address, and it gets confused with the profile setting constantly — including in some vendor quick-start guides that use the label “Protocol/Profile” for 51.02. On an ACS880 with an FPBA-01, node address is 51.02 and… Read More: ACS880 PROFIBUS DP Profiles: How to Choose the Right 51.05… »
Most comparisons of these two treat them as rivals picking a fight over the same job. That framing gets the engineering wrong, and it gets one important fact wrong too. BACnet defines LonTalk as one of its own data link layers. Clause 11 of the BACnet standard specifies how BACnet messages ride on the LonTalk protocol. They are… Read More: LonWorks vs BACnet: How the Two Data Models Differ »
The power line channel is the one that fails for reasons nobody wrote down. A surge arrester goes in on the same board. A lighting retrofit lands on the same circuit. Both are perfectly good electrical work, and both can take the network down. ISO/IEC 14908-3 is unusually direct about this. It declines to specify the medium at… Read More: LonWorks Power Line: The 125-140 kHz Channel Explained »