Additional operation panel (AOP-1/AOP-2):
AOP-1: Standard main DGU with 0.5m cable, including 8 buttons and 16 LEDs.
AOP-2: Connected via CANbus, up to 200m away, each DU can connect up to 5 AOP-2.
AOP provides system status indication and power station mode control (such as semi-automatic, automatic, manual, shutdown, etc.).

DM-4 LAN communication network
The communication between internal DGUs adopts DM-4 LAN for system computation, load distribution, and coordinated control.
PCM 4-1 uses a single twisted pair network.
PCM 4-5 can choose dual redundant LAN (to be ordered) to improve fault tolerance.
Long distance applications can be extended through fiber optic converters.
External communication: Supports RS485 Modbus RTU, Modbus TCP/IP (via PCM 4-5 Ethernet), and CANopen (via CAN interface) for easy access to SCADA or alarm monitoring systems.
Power Management
All DGUs run the same software and recognize their respective roles through the Node Switch on PCM 4. x, achieving distributed management. Each DGU can independently perform specific functions, and this design allows modules to be interchangeable as spare parts, ensuring the continuous operation of critical units in emergency situations.
The power management function includes:
Load dependent start/stop: Automatically increase or decrease the operation of the unit based on the total system load.
Programmable startup priority: Start the unit in the preset order.
Load group control: managing the input and disconnection of heavy loads (such as thrusters).
Load Shedding: Automatically cut off secondary loads before overloading.
Control/monitoring of bus tie and shore power circuit breakers.
Symmetric or asymmetric active/reactive load distribution.
Speed controller controls frequency regulation and active power distribution; AVR control achieves voltage regulation and reactive power distribution.
Protection function (ANSI standard)
DM-4 provides comprehensive protection for generators, busbars, and shore power, all of which are time limited features. The following table lists the main protection functions (ANSI numbers in parentheses):
Protection function ANSI level
Speed monitoring device 15 1 step
Overexcitation 24 2 steps
Synchronization check 25 1 step
Generator undervoltage 27 1 step
Bus undervoltage 27B 2 steps
Generator overload 32 2 steps
Generator reverse power 32R in 2 steps
Demagnetization 40 2 steps
Current imbalance 46 1 step
Phase sequence voltage 47 1 step
Circuit breaker failure 50BF 1 step
Generator overcurrent 50 4 steps
Voltage dependent overcurrent 51V 1 curve
Generator overvoltage 59 2 steps
Bus overvoltage 59B 2 steps
Voltage imbalance 60 1 step
Locking (start/synchronization) 68 1 step
Generator over frequency/under frequency 81, 2 steps each
Bus over frequency/under frequency 81B 2 steps each
Electronic locking relay with 86 channels
Speed/Voltage/Frequency Control 90-
Trip relay 94-
Advanced generator protection (engine/governor/fuel failure) 95 optional
Advanced protection (optional): Through fast communication between PMS units and load distribution deviation calculation, faults such as diesel engine, governor or fuel filter blockage can be detected, and the faulty unit can be automatically disconnected before causing serious disturbance, avoiding power loss throughout the ship. Quick load shedding (optional): Based on load deviation calculation, send an immediate load shedding signal to thrusters and other equipment to prevent generator overload. Special protection functions can be customized as needed.

Customized functions and engineering processes
The flexible I/O platform and integrated electrical parameter measurement of DM-4 provide a foundation for developing customized functions, such as:
Advanced load shedding/offloading algorithm
Load allocation for fuel economy optimization
Propulsion interface and control
Custom operating mode
Order process: Due to the highly customized system, DEIF requires customers to directly contact and provide a single line diagram (including generator and circuit breaker) and control concept description. Based on this, the DEIF project engineer completes the engineering design and provides a quotation to ensure that the system perfectly matches the requirements.
8 Utility Software(USW)
Free PC tools (available for download from www.deif.com) support:
USB directly connected to PCM (or connected to PCM 4-5 via TCP/IP)
Software Download and Parameter Setting
Online monitoring of all DGU modules
Alarm monitoring and clock synchronization
Trending Record
Quick Deployment of Installation Wizard
Summary of Technical Specifications
DGU rack
Working temperature: -25~+70 ℃
Vibration level: DNV A+C (3~13.2Hz 2.0mmpp, 13.2~100Hz 0.7g; earthquake level 3~8.15Hz 15mmpp)
Protection level: IP20
Humidity: 97% RH (IEC 60068-2-30 Db)
Installation method: Base installation
EMC/CE: Complies with EN 61000-6-1/2/3/4
Material: UL94-V0 plastic, aluminum shell, steel panel
Weight: 3.2~8.3kg (depending on configuration)
PCM module
Power supply: 24V DC (-25%/+30%), maximum 6A
Battery voltage measurement accuracy: ± 0.8V (8-32V DC)
CAN: PCM 4-1 has 3 channels, PCM 4-5 has 2 channels (125~250 kbps)
RS485: PCM 4-5 Port 1 up to 38.4 kbps, Port 2 up to 115 kbps