| ACD | Start/pickup status |
| ACT |
1. Application configuration tool in PCM600 2. Trip status in IEC 61850 |
| AI | Analog input |
| ASCII | American standard code for information interchange |
| CMT | Communication management tool |
| Cnt | Counter |
| CT | Current transformer |
| DPC | Double-point control |
| DPS | Double-point status |
| EMC | Electromagnetic compatibility |
| Ethernet | A standard for connecting a family of frame-based computer networking technologies into a LAN. |
| HMI | Human-machine interface |
| IEC | International electrotechnical commission |
| IEC 61850 | International standard for substation communication and modeling |
| INS/INC | Integer status |
| IP | Internet protocol |
| IP address | A set of four numbers between 0 and 255, separated by periods. Each server connected to the Internet is assigned a unique IP address that specifies the location for the TCP/IP protocol. |
| LED | Light-emitting diode |
| LSB | Least significant bit |
| MCD | Momentary change detect |
| MMS |
1. Manufacturing message specification 2. Metering management system |
| Modbus | A serial communication protocol developed by the Modicon company in 1979. Originally used for communication in PLCs and RTU devices. |
| Modbus ASCII | Modbus link mode. Character length 10 bits. |
| Modbus memory map | Allocation of accessible protocol data |
| Modbus RTU | Modbus link mode. Character length 11 bits. |
| Modbus TCP/IP | Modbus RTU protocol which uses TCP/IP and Ethernet to carry data between devices |
| MOM | Momentary position |
| PCM600 | Protection and control IED manager |
| PLC | Programmable logic controller |
| PU | Protection unit |
| RS-485 | Serial link according to EIA standard RS485 |
| RTC | Real-time clock |
| RTU | Remote terminal unit |
| Rx | Receive/Received |
| SCADA | Supervision, control and data acquisition |
| SEC | Security violation |
| SI | Sensor input |
| SPC | Single-point status of a controllable object |
| SPS | Single-point status |
| TCP | Transmission control protocol |
| TCP/IP | Transmission control protocol/Internet protocol |
| Tx | Transmit/Transmitted |
| UD | User-definable |
| UDB | User-definable bit |
| UDR | User-definable register |
| UID | Unique ID |
| UTC | Coordinated universal time |
| VT | Voltage transformer |