Modbus to DNP3 Protocol Converter

1. Modbus to DNP3 Protocol Converter Group 24: Joshua Daly, CpE Daniel Doherty, CpE Mac Lightbourn , EE Joseph Wilkinson, EE

3. Controllers like this one alternate which pumps in the lift station are active to maintain the desired flow rate and water level. • Other functions include ventilation control and alarms for high water or odor levels. • Many controllers are networked together and there is no industry-standard network protocol.

4. Modbus vs. DNP3 Project motivation: MPE needs to allow for communication between network nodes that are using these different protocols.

5. Four-Semester Plan Phase I Device Build User Interface Initialization Phase II Network Communications Security

6. Key Specs • Operates between -10 and 80 degrees Celsius • Protects against surges of 120 V • MCU clock has a backup battery that can power the MCU for 12 hours if power is lost • Sends alarm to master device when power is lost • Takes Ethernet input and gives Ethernet output • Allows user to view and change networking parameters • Logs 20,000 events, even when power is lost, with 98% fidelity • Records date and time of each event to millisecond accuracy • Notifies master device of all events with 95% fidelity

8. Four-Layer PCB Design

10. Choosing an MCU

11. Ethernet Integration • Ethernet jacks include integrated magnetic isolation modules • Input and output both feature a dedicated Ethernet controller • Modbus input and DNP3 output interface with the MCU via SPI ports for high speed communications

12. ENC28J60 J00-0045NL

13. Noise Due to SPI Lines • MOSI and MISO signals transmit at frequencies of 10-100 MHz • Rapid logic transitions on these signals combined with the effective series inductance of the traces lead to a field effect • The result is noise

14. Noise Due to SPI Lines • To reduce the noise, we took three measures • We placed pull-up resistors close to the microcontroller • We used large-value resistors for the pull-ups and large-value bypass capacitors • We isolated the MOSI and MISO lines with copper ground

15. Push Buttons and LEDs

19. Coding Environments • Visual Studio • Used while PCB board was in development • Familiar environment • Code Warrior • Freescale MCU • Optimization of .s19 file

20. Firmware Overview • Creation of data Structs to maintain parameters • Menu system • Allows user to adjust stored parameters • Strict requirements from the sponsor • Initialize all components on the PCB • Handle all button functionality

21. Firmware Challenges • Project requirements changed midway through • Integration of all parts on PCB • Delayed action based on buttons • Code must be well documented and easily modified

22. Data Storage • Stored in contiguous blocks • Storage requirements • Factory defined • User defined

23. Buttons • Required Guidelines • Button Functionality • Menu Navigation • Time Delayed press

25. Screen • Display Screen • 3 7-segement displays • Mimic the current display used by MPE • Allows user to visually navigate and set parameters

26. Power Subsystem

27. Power Supply Requirements Takes in 24 V DC • This supply is shared with other components in the lift station control panel • This is a low voltage in comparison to other devices being used in industrial applications • The low voltage bypasses some of the testing requirements for meeting UL standards

28. Power Supply Requirements Surge Protection • Must handle currents up to 80 A • Must correct irregular voltages • Multiple devices are connected in a shunt configuration for combined benefits

29. Power Supply Requirements

30. Input Surge Protection

31. Power Supply Requirements Must be fed through a DIN rail mount • All devices in the lift station control panel attach to one rail • Mount also serves as chassis ground for added surge protection

32. DC/DC Converter • Voltage is stepped down to 3.3 V and then fed to the power plane • To conserve power, a passive switching regulator was chosen • Our configuration is a common circuit with extensive application notes

33. Financials