Sensors in Design 2012: Sensor Communications in Harsh Environments Class Number SID-401 Mike Fahrion B&B Electronics State of the Art Sensing: 132 AD
And today Image sensor Capacitive touch screen GPS Compass Proximity sensor Light sensor 3 axis accelerometer Gyroscopic sensor GPIO WWAN WLAN WPAN Battery powered The Point? The ways in which we interface physical data are changing And the rate of change is accelerating
Trends in Sensing MEMS, nano technologies Intelligent sensors embedded local processing power Low power or zero power Dedicated wireless technologies Smaller Smarter Less Power What do These Trends Mean? Profound increase in number of sensors deployed Increasingly challenging locations Network boundaries are relentlessly stretched to reach them
Communications at the Edge Future sensors are not just passive inputs they re smart We re taking networking into environments that neither Metcalf nor Cisco envisioned Goodbye RS-232 Reports of my death Forecast: 4% growth in 232 and 485 chipsets Tips & Tricks RS-232 Tens of meters Poor noise immunity Tens of kbps Isolation recommended RS-485 1200 meters Excellent noise immunity Hundreds of kbps Unbalanced twisted pair Isolation required Resist the temptation to terminate
Serial Solutions - Extend Serial Solutions - Isolate
Serial Solutions - Convert USB Ubiquitous with rapid adoption in instrumentation of all kinds Convenient PC-to-peripheral interface; fast, integrated power Tips and Tricks 5 meter limit is real Troublesome connector use high retention versions Twisted pair = inherent noise immunity, but designs are typically consumer grade Use care prone to EMI No isolation be careful when interfacing to the physical world! O/S and applications vary in their reaction to EMI errors
USB Solutions: Extend Extend USB over Cat5 cable or fiber Or, extend USB over a LAN/WAN with USB to Ethernet bridging USB Solutions: Isolate Break the ground loop between devices USB to Serial, or USB to USB
USB Solutions: Convert Easily convert USB to 232/422/485 Single or multiple ports Always recommend isolated converters Convenient no external power required USB Solutions: Connector Standard USB connector a bit wimpy Use enhancedretention connectors Strong enough to pass UL Class 1 Div 2 hazardous location requirements (15N-m)
Ethernet The world has gone IP IPv6, 6lowPAN are enablers for sensor networks Strategy: Convert to IP as quickly as possible Device management, broad toolsets, unequalled interoperability Ethernet Solutions: Extend Wired DSL technology based DSL allows use of any copper pair Typically capable of >>1000 meters Ideal for retrofits
Ethernet Solutions: Extend Wireless Highest performance solutions are 802.11 based 802.11n enables 150 Mbps or more Advanced antenna technology provides range up to 15 km Ethernet Solutions: Convert Readily connect 232 and 485 devices to Ethernet Plethora of I/O adapters available The faster you convert to IP, the faster you get to standards-based tools and infrastructure
Wireless - WWAN - Cellular Cellular provides managed infrastructure with very good (almost great) reach Data plans becoming more M2M friendly Strategic market for wireless carriers One cellular backhaul connection can support hundreds of local sensors Wireless WLAN - WiFi Pervasive interoperable- free infrastructure but your responsibility Beginning to address sensor market with lite chipsets adapted to micro power and low BW requirements Wins the convert to IP strategy race
Wireless WPAN Bluetooth 4.0 technology to watch Maximum component volumes, R&D Smart phones are ubiquitous gateways Chipsets: where goes Wi-Fi, also goes BT4.0 10-300m, low latency, high efficiency Optimized for sensor data Summary Technology advances are enabling prolific sensing Sensors systems design will become synonymous with network design Serial USB Ethernet Wireless technologies will each play a part IP based technologies are expanding boundaries and reach in preparation