Transcript Authors and Poets of the Spanish Speaking World

Modbus to DNP3 Protocol Converter
Group 24:
Joshua Daly, CpE
Daniel Doherty, CpE
Mac Lightbourn , EE
Joseph Wilkinson, EE
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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.
Modbus vs. DNP3
Modbus
DNP3
Created
Market
1979
Widely used in all
SCADA industries
1993
Sometimes used
in water/
wastewater
applications
Difficulty of Equipment
Implementation
Costs
Records timeEfficiency (bytes
Open
stamped event transferred for a given
Standard?
sequences?
bandwidth)
Low
$100+
No
With Difficulty
Average
High
$500$3000
Yes
Yes
Very High
Project motivation: MPE needs to allow for
communication between network nodes that are
using these different protocols.
Four-Semester Plan
Phase I
Device
Build
User Interface
Initialization
Phase II
Network
Security
Communications
Key Specs
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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
Four-Layer PCB Design
Choosing an MCU
Microchip PIC32
TI Stellaris ARM
Cortex M3
Freescale
MC9S12NE64
Freescale
MC9S12XDP512
Price/unit
(bulk purchases)
$1.58+
$1.00+
$6.93+
$13.07+
Pins
28, 36, or 44
64, 100, 144, or 156
80 or 112
80, 112, or 144
Processor Speed
80 MHz
Memory
128 KB SRAM
80 MHz
256 KB SRAM, 32
KB Flash
16 MHz
64 KB Flash, 8 K
RAM
80 MHz
512 KB Flash, 64 KB
SRAM
Cheap/free dev
Special
tools; extensive
Considerations
application notes
Ethernet-ready
XGate coprocessor
Ethernet-ready
module; Nonwith application
multiplexed external
notes; already
bus interface; in
widely used by
same family as MCUs
the sponsor
used by our sponsor
Ethernet Integration
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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
ENC28J60
J00-0045NL
Noise Due to SPI Lines
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MOSI and MISO signals transmit
at frequencies of 10-100 MHz
𝑋𝐿 = 2𝜋𝑓𝐿
Rapid logic transitions on these
signals combined with the
effective series inductance of the
traces lead to a field effect
The result is noise
Noise Due to SPI Lines
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1.
2.
3.
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
Push Buttons and LEDs
Coding Environments
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Visual Studio
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Used while PCB board was in
development
Familiar environment
Code Warrior
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Freescale MCU
Optimization of .s19 file
Firmware Overview
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Creation of data Structs to maintain
parameters
Menu system
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Allows user to adjust stored
parameters
Strict requirements from the sponsor
Initialize all components on the PCB
Handle all button functionality
Firmware Challenges
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Project requirements changed
midway through
Integration of all parts on PCB
Delayed action based on buttons
Code must be well documented and
easily modified
Data Storage
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Stored in contiguous blocks
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Storage requirements
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Factory defined
User defined
Buttons
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Required Guidelines
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Button Functionality
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Menu Navigation
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Time Delayed press
Screen
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Display Screen
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3 7-segement displays
Mimic the current
display used by MPE
Allows user to visually
navigate and set
parameters
Power Subsystem
Power Supply Requirements
Takes in 24 V DC
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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
Power Supply Requirements
Surge Protection
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Must handle currents up to 80 A
Must correct irregular voltages
Multiple devices are connected in
a shunt configuration for
combined benefits
Power Supply Requirements
Type of Device
Lifetime-number of
surges
Response Time
Transient Voltage Suppression Diode
1 ps
Metal Oxide Varistor
1000 surges
1 ns
Zener Diode
infinite
1 us
Gas discharge tube
20 surges
5 us
Input Surge Protection
Power Supply Requirements
Must be fed through a
DIN rail mount
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All devices in the lift station
control panel attach to one rail
Mount also serves as chassis
ground for added surge
protection
DC/DC Converter
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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
Financials
Component
Clock
Clock-Back Battery
Microcontroller
Switching Regulator
Schottky Diode
TVS Diode
Inductor
LCD Driver
3-Digit 7-Segment
Display
Ethernet Controller
Ethernet Connector
Super-Red LED
Cyclone Pro
Programmer
Metal Oxide Varistor
Din Rail Connector
Case
PCB
Pin Connector
Resistor
Capacitor
Total
Price
$2.34
$4.28
$22.85
$3.75
$0.55
$0.73
$3.56
$1.75
$2.91
Quantity
Total
4
1
1
1
1
1
1
1
1
$9.36
$4.28
$22.85
$3.75
$0.55
$0.73
$3.56
$1.75
$2.91
$5.83
$4.73
$1.08
$298.80
2
2
2
1
$11.66
$9.46
$2.16
$298.80
$0.56
$1.54
Donated
$80.00
$0.15
$0.02
$0.12
1
1
1
1
3
17
20
$0.56
$1.54
Donated
$80.00
$0.45
$0.34
$2.40
$457.11
Completion Timeline
Research
Hardware
Firmware
Testing
Overall
0
10
20
30
40
50
60
70
80
90