MQTT runs on top of TCP. That works well almost everywhere it is deployed: on embedded devices, gateways, servers, and desktop tools. There is one environment, though, where it does not work directly: the browser. A web page cannot open a raw TCP connection, which means a JavaScript MQTT client cannot connect to a broker over plain MQTT… Read More: MQTT Over WebSockets Explained: Browsers, Ports, TLS »
Both protocols certify safety up to SIL3, Cat 4, PL e. Both use the Black Channel principle. Both have been deployed for nearly two decades and are used extensively across industries worldwide, with very large installed bases. On paper, CIP Safety and PROFIsafe look almost interchangeable. In practice, choosing between them is one of the most consequential decisions… Read More: CIP Safety vs PROFIsafe: An Honest Comparison of SIL3 Safety… »
Here is the question every engineer eventually asks: how can you trust an Ethernet packet to stop a hydraulic press? Standard Ethernet drops packets. Switches buffer and re-order them. Cables get unplugged mid-cycle. Yet CIP Safety lets a safety PLC monitor an emergency stop button over the same network that carries your I/O and your HMI traffic —… Read More: CIP Safety Explained: How EtherNet/IP Carries SIL3 Safety Data »
Pick the wrong industrial Ethernet protocol for a new machine and you live with it for 15 years. Wrong drives. Wrong I/O. Wrong engineering tools. Wrong training. That is why the PROFINET vs EtherCAT question — sometimes asked as EtherCAT vs PROFINET — matters more than the spec sheet suggests. Both protocols are real-time Ethernet standards, both are… Read More: PROFINET vs EtherCAT: An Honest Comparison for Real Projects »
EtherCAT is the protocol you reach for when 1ms is too slow. Motion control, multi-axis robotics, high-speed test rigs, anything synchronized down to the microsecond — that is EtherCAT territory. It looks like Ethernet, runs on the same cables, uses standard RJ45 connectors. But under the hood it does something no other industrial Ethernet protocol does: it reads… Read More: EtherCAT Protocol Explained: The Trick That Makes It Fast »
MQTT relies on long-lived TCP connections to push messages efficiently in both directions without polling. That design works well when connections behave the way TCP says they will, and breaks down badly when they do not. On mobile, cellular, and satellite links, a connection can quietly stop carrying data while still looking, to both sides, as if it… Read More: MQTT Keep Alive & Client Take-Over Explained »
MQTT is built to run over networks that are not reliable, so it has to assume that clients will sometimes vanish without warning. A client can drop because its battery died, its radio lost signal, its host crashed, or anything else that prevents it from sending a normal disconnect. The rest of the system needs a way to… Read More: MQTT Last Will and Testament (LWT) Explained »
In MQTT, a publishing client has no guarantee that a subscribing client will actually receive its message, because pub/sub decouples them. The publisher’s only guarantee is that the message arrives at the broker; from there, delivery to subscribers depends on who is currently subscribed. Similarly, a client that has just connected and subscribed has no guarantee about when… Read More: MQTT Retained Messages Explained: Last Known Value »
MQTT does not behave like a classical message queue, but under specific conditions it can queue messages for clients. That capability is one of the protocol’s most important reliability features for devices on unreliable networks, and it depends entirely on a concept called the persistent session. Understanding when a session is persistent, what the broker stores in it,… Read More: MQTT Persistent Sessions & Message Queuing Explained »
Quality of Service, almost always written QoS, is the agreement between the sender of a message and its receiver about the guarantee of delivery for that specific message. It is one of MQTT’s defining features and the single biggest reason the protocol works well over networks that are slow, congested, or unreliable. Rather than forcing every application to… Read More: MQTT QoS Levels Explained: QoS 0, 1 and 2 »