3.3 Abbreviations and symbols
| Ctrl | Controller |
| DA | Data Access |
| HDA | Historical Data Access |
| HMI | Human-Machine Interface |
| IEC | International Electrotechnical Commission |
| MES | Manufacturing Execution System |
| PLC | Programmable Logic Controller |
| SCADA | Supervisory Control And Data Acquisition |
| UA | Unified Architecture |
| XML | Extensible Markup Language |