Tag: FOUNDATION Fieldbus instrumentation

Feedback obtained from industrial users of FF reveal a common pattern: Fieldbus is a powerful and reliable technology, but only if it is properly installed. Poor installations, usually driven by a desire to minimize capital expenses, will cause numerous problems during commissioning and operation. One relatively easy way to avoid problems caused by short-circuits in…

Fieldbus devices require far more attention in their initial setup and commissioning than their analog counterparts. Unlike an analog transmitter, for example, where the only “configuration” settings are its zero and span calibration adjustments, a FF transmitter has a substantial number of parameters describing its behavior. Some of these parameters must be set by the…

Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to catalogue data, while in other instances the blocks execute specific algorithms useful for process measurement and control. These “blocks” are not physical entities, but rather abstract software objects – they exist only as bits of data and instructions in computer…

Like so many other industrial data networks, FOUNDATION Fieldbus is an “unswitched” or “broadcast” type of network. This means all data transmissions by all devices on a network are sensed by all the other devices. In other words, there are no private messages between two devices on a shared network: every device “hears” every transmission…

Layer 1 of the OSI Reference Model is where we define the “physical” elements of a digital data network. The H1 FF network exhibits the following properties: Two-wire (ungrounded) network cable 100 ohm (typical) characteristic impedance DC power is conveyed over the same two wires as digital data 31.25 kbps data rate Differential voltage signaling…

FOUNDATION Fieldbus is a standard for digital field instrumentation enabling field instruments to not only communicate with each other digitally, but also to execute all continuous control algorithms (such as PID, ratio control, cascade control, feedforward control, etc.) traditionally implemented in dedicated control devices. In essence, FOUNDATION Fieldbus extends the general concept of a distributed control…