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December, 2019 - Vol 12, Issue 7
CEPD Broomfield and CEPD Loveland Offices
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In This Issue
IEEE Denver Meeting
Transmission Lines
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IEEE Denver Meeting
Real Time Monitoring of Industrial Machines using AWS IoT 
by Dr. Stephan Gerali
We will learn how information technology may be teamed up with Amazon Web Services (AWS) to deliver an integrated Internet of Things (IoT) solution for data capture, data transformation, data storage, data analytics and data visualization for real time monitoring of industrial machines used in the IoT manufacturing process. This presentation will cover the deployment of a full IoT solution to include: Kepware ServerEX for connectivity to industrial protocols, AWS IoT Core for IoT data processing, Amazon S3 for scalable storage of IoT data, MTConnect for a common data model for industrial machine telemetry data, Amazon EMR for interactive analytics on IoT data, Tableau for visualization of IoT data and SIAT for automated anomaly detection for industrial telemetry data. In addition, we will summarize the future roadmap for other AWS IoT Services.
Date December 12, 2019
Time 6:00-8:00pm
Where University of Denver
2155 East Wesley Avenue
Denver, Colorado
Building: Ritchie Engineering Room: 410

Please register as space is limited.
Website IEEE Denver
Transmission Lines - They are part of your circuit design
It may seem that you only need to worry about transmission line design if you are a power distribution or RF engineer :-).  If you are involved in high speed circuit design, transmission lines will occur in your trace routing and your cabling.  A poorly designed transmission line will result in multiple reflections and standing waves, which appear as overshoot, undershoot, ripple, and glitches on an oscilloscope. We have found there are a few rules of thumb to keep in mind to simplify choices made in transmission line design.
  • Determine which signals in your schematic should follow transmission line guidelines.  These will be the clock distribution for your microprocessor and FPGA, controlled impedance data busses, data communications (USB, RS485, etc.), antenna and RF signal chains.  Anymore, just about everything!
  • Use a PCB impedance of 90-120 Ohm for differential signals, and 45-60 Ohms for single ended signals. PCB transmission line impedances can usually be considered purely reactive, and the source and termination resistors are not part of the transmission line.  
  • Be aware of the internal drive and load specifications of integrated circuits, these values become part of your source and load impedances. 
  • Get the design right before releasing it to manufacturing because it is difficult to measure and debug transmission line impedance after fab and assembly.
  • For minimal reflection, and 1/2 the internal source's amplitude at the termination, drive and terminate the transmission line with its characteristic impedance. Place the source resistance close to the driver and the termination resistance close to the end of the line.
  • An open circuit termination causes a 100 percent in phase additive reflection and thus the full internal source's amplitude at the end of the line. A short circuit causes a 100 percent out of phase cancelling reflection and thus zero amplitude at the end of the line.
  • Consider methods which only terminate the AC portion of the signal to minimize DC power loss.
  • For single ended CMOS clock traces, it is usually not desirable to receive only 1/2 the signal at the end.  In this case, drive the trace with a matching source resistance, but only lightly (>5X) terminate the signal at the end.  Interestingly, this will cause a single reflection off of the high impedance load, which will terminate in the source resistance when it travels back.
If you would like help developing a new product or if your projects are understaffed, CEPD can help. Our staff draws on years of diverse product design experience to provide creative and timely solutions for your product needs. Some of our specialties include:
  • Technical Project Management
  • Embedded Systems Hardware and Software
  • Digital Signal Processing (DSP)
  • Data Acquisition
  • Wireless Sensor and Telemetry Systems (Zigbee, Cellular, VHF, Bluetooth, ANT+, etc.)
  • IOT
  • Control Systems
  • Programmable Logic: FPGA / PLD
  • Analog Circuit Design
  • Switching Power Supply Design
  • Battery Charging (all Chemistries)
  • PCB Design and Layout
  • Analysis, Test and Documentation
We provide cost effective and expedient design options for our clients, regardless of the project's complexity.  Our detailed proposals, accurate estimates and time schedules will help you manage each phase of the project. 
The Staff of CEPD, Inc.
© 2019, CEPD, Inc.

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