Development of Communication and Control (C2) Subsystems
AIF Research Forum, Fredericton, New Brunswick, May, 19, 2006
Julian Meng and Shane Barnes
Task Description
• Development of cost-effective communication and supervisory control technologies for DPG.
• Concentrate on internet access and low-cost point-to-point (multipoint) wireless solutions.
• Simple but effective link between Energy Control Center (ECC) and desired DPG device.
DPG Network
DPG C2 Requirements
• Requirements: Modular, Reliable, Flexible
• Bandwidth: Low, kbps (based on anticipated control requirements)
• Distance: Variable
• Control protocol: MODBUS compliant
Deliverables
• Solutions for short and long distance communication links to form a DPG network.
• Hardware and software for communication links.
• Control interface: ECC-DPG.
• Demonstration of reliable field operation.
DPG Communication System
• System components: WAN (Internet), LAN (unlicensed serial radio), Gateway (cellular radio)
DPG Communication System
Scalable Point-to-point Solution
• Low-cost unlicensed (900 MHz ISM band) radios for Gateway to DPG link
• Maxstream, Microhard, others
• Cost: $200 US (low end) to $1500 US (high end)
• Can radios achieve performance of stated specifications?
Gateway Solution
• Cellular Modems: Airlink Redwing ($500 US)
• Low cost wireless access to the Internet
Low-cost Radio Specifications
Test Bench
• Performance expectations of low-cost radio solutions must be managed.
• Field deployment testing is difficult.
• RF test bench was developed to test and validate performance of radios under varying conditions.
• Components include: various RF components, spectrum analyser, signal generator and FPGA channel simulator
Test Bench
• Performance expectations of low-cost radio solutions must be managed.
• Field deployment testing is difficult.
• RF test bench was developed to test and validate performance of radios under varying conditions.
• Components include: various RF components, spectrum analyser, signal generator and FPGA channel simulator
Test Bench
FPGA-based Channel Simulator
Characteristics: Low-cost Quick data collection & analysis Real-time simulation of real-world channel
conditions Critical performance comparison Problem identification before costly market failure Re-configurable FPGA for broad range of
scenarios
FPGA-based Channel Simulator
• Free space loss• Propagation delay and multipath reflections• Additive white Gaussian noise• Multi-access interference• Narrowband interference
PER Sensitivity Performance 9600 kbps
-116 -115 -114 -113 -112 -111 -110 -109 -10810
-3
10-2
10-1
100
Free-Space Path LossInput Power: 20 dBm ; RF Data Rate: 9600 bps
Pac
ket-
Err
or-R
ate
Received Power, dBm
Microhard Spectra 910
MaxStream XStream-PKG
PER External Interference Performance 9600 kbps
-120 -115 -110 -105 -100 -95 -90 -85 -8010
-3
10-2
10-1
100
Multiple Access Interference
Input Power: 20 dBm ; RF Data Rate: 9600 bps ; Interferer Code: x7 + x1 + 1
Pac
ket-
Err
or-R
ate
Received Power, dBm
Microhard Spectra 910
MaxStream XStream-PKG
MODBUS Protocol
Control layer: Internet based Open standard Scaleable Universal recognition
MODBUS Protocol
Gateway
PLC
HMI
Drive
I/O
I/O
Gateway Gateway
PLC
I/O
I/O
DeviceDevice
MODBUS on TCP/IP
Drive PLC HMIM
OD
BU
S o
n M
B+
MO
DB
US
on
RS
232
MO
DB
US
on
RS
485
PLCI/O I/O
MODBUS Communication
Where we are …
• Two low-cost P-to-P radios have been bench tested.
• Simple Gateway/P-to-P solution was shown to be successful. Meaning: From anywhere in the world where we can access the internet, we can observe/control the DPG conditions.
• The selected (as are most) telemetry radios are MODBUS capable to allow for flexibility, interoperability and industry compliance.
Where we need to be …
• Communication layer utilization by the application layer i.e. ECC to DPG.
• Bench level mockup.
• Field testing and validation.