Glossary

Definitions for the terms used across this documentation. The first group is JasperNode-specific; the second translates general industrial-automation vocabulary for engineers arriving from other fields.

JasperNode terms

Tag : A named value at a path — the only data structure you really need to learn. Holds a value, live stats, and durable properties. See Everything is a tag.

Tag ID : A tag’s address: its path plus name, e.g. factory/line1/temperature.

rid : A tag’s internal identity, shown on its Basic tab. It survives renames, so moving a tag never re-points a subscription at the wrong data.

Value type : One of number, boolean, string, or bytes.

Source : Who set a value — ui, script, system, or a specific connector. Recorded on every write.

Quality : A derived health flag on a value: good, stale, uncertain, or unknown.

Property : Durable per-tag metadata: description, value type, decimals, the attached script, and connector linkage.

Script : A small async JavaScript function attached to a tag that computes its own tag’s value when its inputs change. It declares the tags it reads in the code, via on() / read(). See Logic & the Logic Cycle.

on("path/name") : Reads a tag’s value and declares it a trigger — a change to it runs the script. A script’s triggers are just its on() call sites, read out of the code at deploy.

read("path/name") : Reads a tag’s value as a read-only input — the script can use it but a change to it does not run the script.

Trigger : A tag whose change causes a script to run — declared by calling on() on it in the script’s code.

cache : A per-script object that persists across runs (for counters, timers, latches).

Logic Cycle : JasperNode’s event-driven script executor. Runs only the scripts whose triggers changed. The PLC analogy is an interrupt/event task.

High Performance Cycle (HPC) : A planned, deterministic, time-driven executor for continuous control and safety logic. Not in the current release.

Connector : A module that bridges the tag tree to one external system. The only thing that performs I/O. See Connectors.

Kind : A connector’s category: ot (fieldbus), it (network/cloud), or system (built-in service).

Direction (in / out) : Declared per mapping. in = device→tag (input); out = tag→device (output). Enforced by the runtime.

Cold-start : The (re)start behaviour where a connector reads inputs and re-announces values so dependent scripts react correctly.

Deploy Gate : The test-before-deploy state machine that holds process-affecting changes until they pass their test, and holds field-driving ones until a human signs off. See The AI agent.

Editor / Viewer : Roles. Editor = full edit plus the AI agent. Viewer (read-only) is planned for a later release.

JasperX : The cloud service that provides sign-in and the AI agent.

General automation terms

PLC (Programmable Logic Controller) : A ruggedised industrial computer that runs control logic on a cyclic scan. JasperNode targets the same job with a different model — see JasperNode vs. a PLC.

Scan / scan cycle : A PLC’s repeated execution of its whole program. JasperNode is event-driven instead — logic runs on change, not every scan.

OT / IT : Operational Technology (the machinery, fieldbuses and controllers on the plant floor) vs Information Technology (networks, servers, databases, cloud). JasperNode connectors are split along this line.

Fieldbus : An industrial network connecting controllers to sensors, actuators and drives (e.g. EtherCAT, PROFINET, Modbus).

Modbus : A simple, ubiquitous industrial protocol. Data lives in coils (1-bit) and registers (16-bit) addressed by number, over TCP or serial (RTU).

Register / coil : Modbus storage units — a 16-bit register (numbers) and a 1-bit coil (on/off).

EtherCAT : A high-speed, low-latency fieldbus for real-time distributed I/O and motion control.

S7 : Siemens’ family of PLCs (S7-300/400/1200/1500, LOGO!) and the protocol used to talk to them.

MQTT : A lightweight publish/subscribe messaging protocol common in IIoT.

Sparkplug B : A convention on top of MQTT that standardises how industrial devices announce and publish data.

SCADA : Supervisory Control and Data Acquisition — the dashboards/historians that monitor and supervise plant equipment.

HMI (Human-Machine Interface) : The operator screen for a machine or process. JasperNode includes an HMI Server connector.

Setpoint : A target value for a control loop (e.g. desired temperature).

Tag / point : In SCADA/PLC terms, a named process value — the same idea as a JasperNode tag.

Historian : A database of time-stamped process values. JasperNode streams to one via the InfluxDB connector.

Retentive memory : PLC memory that survives a power cycle. In JasperNode every tag plays this role — values and properties are saved as they change.

Forcing : Overriding an input/output for testing. In JasperNode you disable the owning connector, then write the tag from a script or the UI.

SIL (Safety Integrity Level) : A measure of safety-function reliability (IEC 61508). JasperNode targets SIL-3 in a later release on certified hardware; the current release is not safety-certified.