---
name: class-object-engineering
description: >-
  CI Server R1.03 PROCESS Service: trigger groups, classes and objects. Use when the user wants
  to create a trigger group, write, compile or change a class (Traditional PROCESS language or
  Java), use signals, attributes, prompts, timers or template items in a class, create objects
  from a class (with prompt answers), let an object create its own items, reset a class after a
  change, read or change object attribute values, see which item a signal uses, load or remove
  classes and objects with quick load files, or check PROCESS Service with opcdbg (database
  check, object status, executor statistics). Sources IM 36K10L10-01EN, IM 36K10P10-01EN,
  IM 36K10P11-01EN, IM 36K10G10-01EN (Tutorial).
---

# Class and object engineering (R1.03)

Background: `knowledge/manuals/IM36K10L10-01EN.md` (processes, `opc.sup`, `opcdbg`, data
store), `IM36K10P10-01EN.md` (Traditional language), `IM36K10P11-01EN.md` (Java),
`IM36K10G10-01EN.md` chapter 5 (Tutorial). Known issues for PROCESS Service:
`knowledge/manuals/IM36K01A50-01EN.md` (PROCESS 1.10).

Rules:
- Run `system-check` first; follow the user's chosen way of working.
- Creating, changing or resetting classes and objects changes the running system; objects can
  write to items (and through them to devices). Test on a test system or with the user's
  approval.
- Deleting an object deletes the items it created (and their history links).
- `opcdbg`: read-only actions only, unless the user approves (task `opcdbg-checks.md`).

| Task | File | Status |
|---|---|---|
| Trigger group, class (compiled on load) and object via quick load; compile errors; remove | `tasks/load-class-object.md` | verified |
| Traditional class with prompts/attributes, signals from the object's section, items created from a template, input check; change an attribute at runtime | `tasks/traditional-class.md` | verified |
| Java class: attach and create items, signal trigger, system log message | `tasks/java-class.md` | verified |
| Change a class that has objects: compile, reset with `opcdbg` | `tasks/change-reset-class.md` | verified (`dssqld` reset does not work, ISS-028) |
| `opcdbg` checks: database check, class/object details, object status, executor statistics, dumps | `tasks/opcdbg-checks.md` | verified |
| Language reference (statements, operators, built-ins, DSS routines; Java API) | P10 / P11 summaries | from docs, main parts verified |
| `opc.sup` settings (executors, priorities, statistics, PRINT) | L10 summary §2 | read-only check; changing not practiced |
| Containment, inheritance, timers, alarms, STEP state machines, DSS routines | P10 / P11 summaries | from docs |