- Data Acquisition Processing
DTU acquires digital and analog signal from station plus processing and storage in the memory and ready to transmit the data
back to communication server or control center.
- Sequence of Event Report
DTU provides the SOE function (Sequence of Event) to monitor the status and sequence, or any changes of equipments at the
station. An event is defined as a single change of state. Each time an event is detected, RTU will time tag the event and
save a description of the event and the time tag in a first in first out (FIFO) buffer. There is 1024 events buffer in DTU.
- Control Output
Two types of control command can be transmitted from the Master Station to devices in the power system via the DTU. One is
Trip / Close command, the other is Direct Set point command.
There are two types of control output using Trip / Close command. One is ON / OFF operation output to control CBs, ABSs and
the other is Regulation operation output (Raise / Lower) to control the position of transformer taps. Two types of Trip / Close
commands are supported.
- Communication Function
The communication function of DTU can be divided into internal communication and external communication.
- SCADA Master: CDC Type II, DNP3.0, IEC 870-5, CDT (China).
- DTU Sub-Master: Modbus RTU, DNP3.0, IEC 870-5.
- IED: Modbus RTU, DNP3.0.
- Self-Diagnostic Function
DTU is designed with self-diagnostic function. Every abnormal status of DTU is recorded as System Event, or indicated by LED
excitation on the panel. The System Event record can be retrieved by test set and store in its hard disk, which is very easy
to detect errors in maintenance.
- Programmable Algorithm Function
DTU have the capability of user definable "Sequential Algorithm". The "Sequential Algorithm" within DTU can communicate through
a common variable database which consists of analog inputs, digital inputs, accumulator inputs, pseudo points, alarm (system)
status, digital output, and system clock.