The popularity of smart meters with built-in intelligence and two-way communications continues to rise, because of the benefits they offer both to utility companies and to consumers. The utility suppliers can set up dynamic pricing to incentivise consumers to shift peak loads, while consumers can better track their usage and decide when not to use appliances that consume substantial amounts of power to reduce their energy bills.
What is a smart meter?
Although the definitions vary somewhat, a smart meter monitors energy, gas or water consumption and displays this in real-time, typically on an LCD display. The meter also has a communications interface – in the U.S., many companies have standardized on the ZigBee wireless radio as the link to the utility, while in Europe, many utility groups have agreed to use power-line communications. These communication interfaces have to be low power even though they spend most of their time in a “sleep” or standby mode.
Note that many connections are not directly from the smart meter to the utility, but instead to a local gateway or router that then uses a wireless or wired Internet channel for the long-haul communication from the gateway to the utility. Additionally, some meters communicate over GSM or GPRS mobile phone networks; they require a SIM card to do this.
As meters become smarter, they are taking on more complex tasks like time-of-use billing and automatic meter reading (AMR). These tasks call for more powerful microcontrollers, wireless radios, information-rich LCDs, and real-time-clocks (RTCs) to supplement the analogue front end (AFE). While first-generation meters use multiple chips to fulfil these functions, the utilities are looking to component and meter suppliers to provide more highly integrated devices to help drive down costs and footprint.
Meanwhile, recent trends are imposing further challenges on smart meter designers. In the past, meters could be protected from environmentally challenging locations simply by installing them within purpose-built cabinets; the cabinets could provide all the protection necessary to handle the prevailing conditions. Nowadays, though, constraints on both space and cost mean that the luxury of this outer enclosure is often no longer an option. The onus falls instead onto meter manufacturers to build ruggedisation directly into their meter designs. This becomes a critical issue, for example in Australia, where household water meters are typically installed outdoors in back gardens – and when it does rain, it rains heavily.
GradConn offers a range of connectors that help designers overcome these issues in terms of communications capability, ruggedisation and miniaturisation. This includes a wide variety of coaxial cable assemblies, with particular strength in micro coaxial cables for wireless markets.
Overall, GradConn’s Nautilus range of IP67 and IP68-rated connectors gives proven protection from moisture and particle ingress, whether mated or unmated. These connectors achieve their IP67 and IP68 ratings through internal and external O-rings, which prevent ingress through either the centre of the connector or the panel cutout.
SMA connectors are available as rear-mount, front-mount, reverse-polarity rear-mount, and reverse-polarity front-mount. Other IP-rated connector types for bulkhead mounting include TNC, N and BNC.
The bulkhead connectors are specified as part of a complete cable assembly; many assembly options already exist, and can be ordered accordingly. These include cable options to 3GHz, and board-mounting micro connector choices such as IPEX MHF (an alternative to Hirose U.FL), Hirose H.FL, MMCX and MCX, straight or right-angle plugs. MMCX connectors, in particular, are increasingly favoured by the smart meter industry because of their ruggedisation.
The cable assemblies can handle GSM, GPS, Wireless LAN (WLAN), Wi-Fi, Zigbee Z-Wave, EnOcean and Bluetooth wireless communications protocols.
For other configurations, and a wider choice of micro connector types, a useful Coaxial Cable Assembly Builder is available on the GradConn website. This allows engineers to rapidly configure a solution that meets their requirements perfectly.
We referred above to certain types of smart meters that communicate over mobile phone networks, and use SIM cards to do so. GradConn helps smart meter builders meet these requirements with a wide range of Mini, Micro and Nano SIM card connectors available in Push-Push, Push-Pull, Hinged, Dual and Contact configurations. SIM Connectors are available with 6 or 8 contacts and optional PCB locating pegs and metal hold downs. Card detection switches allow electronic detection of SIM card insertion or extraction; this adds an extra two contacts and is sometimes described as 6+2 or 8+2. Low profile options are also available.
These SIM connector options give engineers a wide choice for both ‘easy access’ and ‘fit and forget’ designs. For ‘fit and forget’ installation into anywhere within the meter, the CH03-BH060-A is a popular hinged connector for Mini 2FF SIMs with 6 or 8 contacts and a Normally Open switch. However, Push-Pull connectors that provide easy access at the edge of the instrument are widely used in smart meter design; the CH03-FB is a good example for Micro 3FF SIMs with 6 or 8 contacts. Alternatively, the CH03-DE offers a competitive solution where Push-Push is required for Mini 2FF cards with 6 or 8 contacts, with Micro 3FF variant also available in the CH03-GB. A Normally Open switch is also provided.
In addition to Coaxial and SIM connector products, Gradconn have an industry-leading board to board connector range, in particular fine pitch 1.0-1.27mm versions that are ideal for smart meters. With smaller designs being developed, these micro connectors are great for space saving.
As items that can become visible on the Internet and communicate with cloud-based servers and processing services, smart meters can be considered as typical Internet of Things (IoT) connected devices. GradConn’s ongoing experience with their customers shows that this is part of an ever-increasing and wider trend of making products IoT-ready by building in intelligence and connectivity.
With their wide range of rugged bulkhead connectors, wireless-standard micro connectors, cables and assemblies, and SIM card connectors, GradConn is in an excellent position to facilitate hardware designs for not only smart meters, but also for many other IoT-ready products, with connectors from a single source. For more information please contact GradConn.