Controlling Smart Meters
Many different commands can be sent to Smart Meters. Some are to do with customer configuration such as prices, some are for maintaining the meter and others for security; only particular commands can be used by particular users. The user groups are defined as follows:
- Import Supplier
- Export Supplier
- Gas Supplier
- Registered Supplier Agent
- Electricity Distributor
- Gas Transporter
- Other User.
The commands have been standardised so that meter manufacturers and operators can follow a common operational process, however, many manufacturers have added some additional commands of their own if they thought them to be useful.
There is a high level of security around these commands. The more important commands are sent back to the sending company by DCC for a final check before being sent on to the meter.
The list of standard commands below are for devices such as meters and communication hubs, and have been taken from the Draft Version 1.1 of the DCC User Interface Specification (DUIS) dated 16th December 2015 and published on 17th December 2015.
- Update Import Tariff (Primary Element)
- Update Import Tariff (Secondary Element)
- Update Price (Primary Element)
- Update Price (Secondary Element)
- Update Meter Balance
- Update Payment Mode
- Reset Tariff Block Counter Matrix
- Update Prepay Configuration
- Top Up Device
- Update Debt
- Activate Emergency Credit
- Display Message
- Restrict Access for Change of Tenancy
- Clear Event Log
- Update Supplier Name
- Disable Privacy PIN
- Read Instantaneous Import Registers
- Read Instantaneous Import TOU Matrices
- Read Instantaneous Import TOU With Blocks Matrices
- Read Instantaneous Import Block Counters
- Read Instantaneous Export Registers
- Read Instantaneous Prepay Values
- Retrieve Change Of Mode / Tariff Triggered Billing Data Log
- Retrieve Billing Calendar Triggered Billing Data Log
- Retrieve Billing Data Log (Payment Based Debt Payments)
- Retrieve Billing Data Log (Prepayment Credits)
- Retrieve Import Daily Read Log
- Retrieve Export Daily Read Log
- Read Active Import Profile Data
- Read Reactive Import Profile Data
- Read Export Profile Data
- Read Network Data
- Read Tariff (Primary Element)
- Read Tariff (Secondary Element)
- Read Maximum Demand Import Registers
- Read Maximum Demand Export Registers
- Read Prepayment Configuration
- Read Prepayment Daily Read Log
- Read Load Limit Data
- Read Active Power Import
- Retrieve Daily Consumption Log
- Read Meter Balance
- Create Schedule
- Read Schedule
- Delete Schedule
- Read Device Configuration (Voltage)
- Read Device Configuration (Randomisation)
- Read Device Configuration (Billing Calendar)
- Read Device Configuration (Identity Exc MPxN)
- Read Device Configuration (Instantaneous Power Thresholds)
- Read Device Configuration (MPxN)
- Read Device Configuration (Gas)
- Read Device Configuration (Payment Mode)
- Update Device Configuration (Load Limiting General Settings)
- Update Device Configuration (Load Limiting Counter Reset)
- Update Device Configuration (Voltage)
- Update Device Configuration (Gas Conversion)
- Update Device Configuration (Gas Flow)
- Update Device Configuration (Billing Calendar)
- Synchronise Clock
- Update Device Configuration (Instantaneous Power Threshold)
- Read Event Or Security Log
- Update Device Configuration (Auxiliary Load Control Description)
- Update Device Configuration (Auxiliary Load Control Scheduler)
- Update Security Credentials (KRP)
- Update Security Credentials (Device)
- Issue Security Credentials
- Set Maximum Demand Configurable Time Period
- Reset Maximum Demand Registers
- Set Device Configuration (Import MPxN)
- Set Device Configuration (Export MPAN)
- Request Handover of DCC Controlled Device
- Configure Alert Behaviour
- Update Security Credentials (CoS)
- Retrieve Device Security Credentials (KRP)
- Retrieve Device Security Credentials (Device)
- Set Electricity Supply Tamper State
- Enable Supply
- Disable Supply
- Arm Supply
- Read Supply Status
- Activate Auxiliary Load
- Deactivate Auxiliary Load
- Read Auxiliary Load Switch Data
- Reset Auxiliary Load
- Add Auxiliary Load to Boost Button
- Remove Auxiliary Load from Boost Button
- Read Boost Button Details
- Set Randomised Offset Limit
- Commission Device
- Read Inventory
- Decommission Device
- Update Inventory
- Service Opt Out
- Service Opt In
- Join Service (Critical)
- Join Service (Non-Critical)
- Unjoin Service (Critical)
- Unjoin Service (Non-Critical)
- Read Device Log
- Update HAN Device Log
- Restore HAN Device Log
- Restore Gas Proxy Function Device Log
- Return Local Command Response
- Communications Hub Status Update - Install Success
- Communications Hub Status Update - Install No SM WAN
- Communications Hub Status Update - Fault Return
- Communications Hub Status Update - No Fault Return
- Request Customer Identification Number
- Update Firmware
- Read Firmware Version
- Activate Firmware
- Request WAN Matrix
- Device Pre-notification
- Record Network Data (Gas).
There are also a small number of messages from DCC rather than from the meters:
(Page updated: 2019-10-18)
- Power Outage Event
- Device Status Change Event
- DSP Schedule Removal
- Command Failure
- Firmware Distribution Failure
- Update HAN Device Log Result
- Change of Supplier
- Device Log Restored
- PPMID Alert.
Questions & Answers
What is the SMETS1 end date?
The government are keen for all SMETS (Smart Meter Equipment Technical Specifications) smart meters to interoperate on one system so customers can switch suppliers easily. To encourage this they are discouraging suppliers installing the older SMETS1 meters and incentivising them to move to the new SMETS2 meters.
If suppliers wanted the installations to count towards their government targets they could not install SMETS1 meters (or upgrade firmware to SMETS1) after 5th December 2018. Note that some suppliers had a special dispensation and were able to carry on until 15th March 2019.
Additionally due to the extra complexity of prepayments meters, the end date for them was 15th March 2019.
However, suppliers can still install SMETS1 meters if they wish, but it will not count towards their government targets. They may do this to use up old meters stocks or where the customer does not yet have a signal from the new DCC system. (Updated: 2020-02-09)
Are smart meters safe?
Yes. Smart meters are subject to the same safety regulations and testing of any in-home technological devices, including baby monitors and mobile phones. Additionally the meters are secure having a security system developed by industry and government experts including GCHQ's National Cyber Security Centre.
A side benefit is that many safety problems are being spotted in peoples homes during installation of the smart meter which would not have been spotted without a visit. (Updated: 2019-10-21)
Can a Smart Meter interfere with my WiFi?
Yes interference can occur for up to an hour while your WiFi and the Smart Meter each find the best channel to avoid each other.
Both your WiFi and the Zigbee network used by Smart Meters operate in the same 2.4GHz radio band and the band is divided into channels. Most modern WiFi routers can scan channels in order to pick the ones with the least interferences from other devices and the Smart Meter Zigbee system can do the same. As some door bells and remote controls can also use the 2.4Ghz band it may take an hour or two for the best channels to be chosen.
If interference problems continue, you can log onto your WiFi router and select the channel manually to see if that helps. It is not possible to override the automatic channel selection on the Smart Meter. (Updated: 2020-01-20)
What is a SMETS2 meter?
Over six million meters have now been installed to the Smart Metering Equipment Technical Specification (SMETS) 2 standard. These are the most advanced meters available and communicate through the Data Communications Company (DCC). Suppliers were obliged by government rules to stop installing SMETS1 meters by 15 March 2019 and only install SMETS2 meters. Suppliers started to install SMETS2 meters in Q2 2017 and in large volumes from autumn 2018. (Updated: 2021-02-17)
When will my SMETS1 meter operate again?
The upgrade and transfer of SMETS1 (Smart Meter Equipment Technical Specifications) meters into DCC's systems is planned to occur between June 2019 and the end of 2022.
For more information see Enrolment and Adoption
on DCC's website.
Provided your meters are on the list of meters which can fit into this process on table SMETS 1 Meters for adoption by DCC
they should start working again during that transfer period. (Updated: 2021-12-06)
What is a CAD?
A CAD is a Consumer Access Device which provides access to your meter data through WiFi. These are relatively new and usually integrated into the IHD (In Home Display) provided by suppliers. One example of such a device is the Chameleon IHD3
The IHD still needs a link to the meters to retrieve the data first so CADs do not provide an alternative solution where the meters and IHD are separated by a large distance. (Updated: 2020-03-05)
How are they tested for accuracy through their life?
Smart meters fall into the MID scheme (Measuring Instruments Directive)
which means they are certified at their introduction to market as being accurate but are not given a certification period as traditional meters used to be. Their life depends on their performance during MID In-service testing (IST)
. The Office for Product Safety & Standards gathers samples of meters from suppliers, if they prove to be in-accurate that type/age of meter will be replaced in customer premises. (Updated: 2019-08-23)
Does my SMETS1 meters have to be replaced?
In early 2018 the government and industry agreed to build interfaces which allow the earlier SMETS1 (Smart Meter Equipment Technical Specifications) Smart Meters to be moved to the new DCC system supporting SMETS2 meters. This means that, although you may have lost Smart functionally when you changed supplier, when it is enrolled into the new DCC system that functionally will come back, and you’ll be able to change suppliers without technical problems. The process of moving the meters across system is called enrolment and adoption
See our Technical page
for a list of SMETS1 meter types that can be upgraded.
What is Zigbee?
is a communication protocol for radio networks. It is designed to be simpler, use less power and be cheaper than other systems and therefore is ideal for mass deployment in Smart Meters.
In Smart Meters the Zigbee protocol is used to communicate between the communications hub, electricity meter, gas meter and IHD (In Home Display). (Updated: 2020-02-09)
Who pays for the meter electricity?
The customer does not pay for the electricity used to power the meter directly as the meter takes its own power from a point before measurement takes place. The power used by the meter will fall into distribution losses which also includes the energy lost through the distribution cables as well. This was also the case with traditional meters.
Ultimately all customers pay for this as a percentage increase which is applied by area. For a technical explanation see Electricity Distribution System Losses
. (Updated: 2020-08-19)
What is Market-wide Half Hourly Settlement?
Market-wide Half Hourly Settlement (MHHS) will allow the electricity industry to move way from average consumption profiles for customers to using half hourly data.
Currently domestic and small business electricity use is modelled on a small number of average usage profiles. Obviously when you add up what was supplied and what was used they are not the same because of the use of average profiles. So the use of half hourly data will improve this and means that suppliers will have a more accurate wholesale energy bill.
This could improve customers' bills as the commercial risk for suppliers is slightly reduced.
This does not change tariffs for customers or what data domestic customers allow their smart meters to send unless they agree.
Can my supply be turned off remotely?
Smart meters have the facility to remotely disconnect and reconnect both the electricity and gas supply. However, most suppliers seem to have decided it is too dangerous to remotely disconnect or reconnect, as in the case of disconnection they cannot always be sure that the customer isn't relying on a supply for serious health reasons and in the case of reconnection the customer may have left a cooker on for example. (Updated: 2015-01-23)
How do I top-up my smart meter PAYG if the mobile network is down?
Normally your PAYG (Pay As You Go) top-up will be sent automatically to the smart meter, however, if the communications link through the mobile network is not available then this cannot happen.
Firstly you can use the emergency credit that most suppliers offer. If that runs out you can enter the long authorisation number that you received when you paid for the credit into the meter or IHD (In Home Display) to apply your credit. This very difficult to do on the meter so use the IHD if you can. (Updated: 2019-10-21)
What is a Dual Band Comms Hub?
The current Communication Hubs have a single band 2.4 GHz HAN (Home Area Network) frequency and are known as Single Band Comms Hubs (SBCH) and should provide HAN coverage between meters and the IHD (In Home Display) in approximately 70% of premises.
For some buildings like blocks of flats or where walls are very thick, the smart meter can't communicate with the Comms Hub. So by mid 2020, a more sophisticated hub with a choice of frequencies will be available. These are called Dual Band Comms Hubs. They use a HAN frequency of 868MHz along with the existing 2.4GHz frequency. Dual Band Comms Hubs (DBCH) are expected to increase coverage to 95% of premises.
What is the HAN range?
The range of the Smart Meter HAN (Home Area Network) is about 15m, but this is reduced by obstructions such as walls and doors. Where the meter is a long way from the location of the IHD (In Home Display), or thick walls are in the way, the current technology (Zigbee at 2.4GHz) won't work. This could be the case for up to 30% of properties.
A different communications method (Zigbee 868MHz) available from mid 2020 will improve this for about 3.5% of properties but that still leaves a large number for whom Smart Meters won't work.
For these final properties, for example where meters are in a basement a long way from the customer's IHD, a separate company has been set up to investigate solutions, prepare contracts and procure the equipment. The company is the Alt HAN Co Ltd
and solutions are expected in 2021. (Updated: 2021-10-03)
Can a Smart Meter replace my Radio Teleswitch?
Yes a Smart Meter can provide similar functionality to the Radio Teleswitch System (RTS)
. RTS is used to stagger the switch on and off times of tariffs such as Economy 7 so that a surge in power doesn't occur from all the storage radiators in the country switching on at the same time.
If you are on a tariff switched by RTS we recommend you speak to your supplier to get a Smart Meter and ask what tariff you can move to. The RTS service uses the BBC Radio 4 long wave signal and is planned to end in March 2023. (Updated: 2021-04-25)
Can I look at my energy usage on the internet?
You will be able to view your energy usage on the internet at some stage. Suppliers are all working on new systems to make this possible. (Updated: 2015-01-23)
How much data is stored on a Smart Meter?
The SMETS2 specification requires the following data to be recorded and stored.
Half-hourly electricity data:
- 13 months of consumption (Active Energy Import)
- 3 months of active energy exported
- 3 months of reactive energy imported
- 3 months of reactive energy exported.
- 3 months of half-hourly consumption
- 13 months of monthly consumption.
Do Smart Meters use 5G?
No Smart Meters currently use 5G. Even in the future a move to 5G is unlikely as the amounts of data transferred are very small and long distance communication is the main requirement. 5G is a higher frequency technology and generally low frequencies are most reliable and capable of penetrating obstructions like buildings, which is why 4G will often work in more places than 5G. Higher frequencies are also more easily scattered by objects. (Updated: 2021-04-07)
Do Smart Meters measure voltage?
Yes, Smart Meters provide a record of voltage. This is of great interest to the Distribution Network Operators (DNOs) as they are responsible for setting the voltage on the network by adjusting the taps on transformers. The voltage on the network is more difficult than ever to control due to varying local generation.
UK Power Networks carried out a project on the Use of smart meter information for network planning and operation
which included voltage.
Also see this document from Western Power Distribution giving their Smart Meter Strategy
. (Updated: 2021-05-03)
Can I lay a cable to help join the devices together?
The meters and IHD (In Home Display) can only be joined through a radio link. This applies to all three standards of meters pre-SMETS, SMETS1 and SMETS2. However, one or two suppliers may be able to offer a zigbee booster, this is similar to the wireless booster you can buy for your home broadband and just plug into a power socket.
Our recommendation would be to let your supplier sort it out, as a communications hub (868MHz) with better reach will be available to suppliers to install with SMETS2 meters where needed from mid 2020. (Updated: 2020-02-09)
What is the gas mirror?
Communications from the comms hub on the electricity meter to the gas mater can be slow and may drop out sometimes. To make the system more efficient the engineers came up with the idea of a "Gas Mirror" which is to keep a copy of the gas meter software in the comms hub.
Any changes such as new firmware destined for the gas meter are transferred to the "Gas Mirror" first and then sent to the gas meter over time. (Updated: 2020-10-24)
Can smart meters be upgraded?
Smart meters can have a firmware upgrade just like your computer or mobile phone. The upgrade will be used to fix faults and add new functionality and should be carried out in the background with little impact on the customer. Indeed this feature is being used to allow SMETS1 meters to be upgraded for the SMETS2 systems; this will allow them all to interoperate. (Updated: 2019-10-21)
Do SMETS2 meters support solar panels?
Yes all SMETS2 meters support solar panels as this was included in the SMETS2 specification. However, this does not mean your suppliers will support it. A lot of work is required in a supplier's back office systems to set up the meter correctly, and process and store the messages required to operate export properly.
We suggest you check with your own supplier whether they can support export yet. (Updated: 2021-02-12)
How does the smart meter record energy generation if a solar panel is installed?
All smart meters will record the export and import separately, and you will be able to see the readings by stepping through them on the meter display. All the meters should show all 4 power quadrants. You can ignore the reactive ones and just look at active import and export.
- Active energy import (Wh) - this is what we are billed for normally
- Reactive energy import (varh)
- Active energy export (Wh) - this is your useful export power
- Reactive energy export (varh).
The bad news is that many companies have not set up their systems to automatically collect or use the export information, as it would have taken time and money they don't have for such a low volume user base. (Updated: 2018-10-02)
What is dithering?
When a Smart Meter loses power and powers up it sends an alert message to suppliers and network operators to let them know. If a large area had lost power and thus a large number of meters were to send these messages at once it would put a heavy load on the communications network. To prevent this the meters "dither", that is to say they all wait a short random period before sending those first messages thus avoiding the simultaneous peak. For the first two years (to September 2018) the dithering period was up to 2 minutes. After that a decision will be made on whether to set it to the default 5 minutes. (Updated: 2016-02-16)
How often will my IHD be updated with data from my meters?
Your IHD (In Home Display) will be updated by your electricity meter about every 10 seconds and by your gas meter about every 30 minutes. The gas meter updates less often in order to preserve its battery life which in normal use is expected to be at least 10-15 years. (Updated: 2020-10-23)
My supplier says my signal is too weak?
Smart meters communicate through mobile communications and so the signal strength is an important factor to consider for installation.
For SMETS1 meters the installer will usually test on site and make a decision there and then whether to install. If there is not a sufficient signal they will usually walk away.
For SMETS2 there are more options. The communications are provided by the Data Communications Company (DCC) and suppliers can check that a premises has communications before visiting a site. Once on site they can check with a signal checking device if the signal is strong enough in the meter location. If it isn’t they can fit a number of different aerials to try to boost the signal. If that doesn’t work an external aerial or an alternative mesh communications method is available in some areas. Even then they can leave the meter de-commissioned and ask the DCC to get the communications working. (Updated: 2017-02-01)
Are Three-phase SMETS2 meters available yet?
What is a HAN-connected auxiliary load control switch (HCALCS)?
Similar to an ALCS (Auxiliary load control switch), a HCALCS allows large domestic loads, such as electric vehicles chargers, to be controlled independently of the main power supply. However, rather than being integrated with the meter directly, the switch is remotely connected via the Home Area Network. This provides more flexibility, avoiding the need for new wiring back to the meter when a new load is connected. (Updated: 2021-04-09)
Can I fit an aerial?
You cannot fit an aerial yourself. All Comms Hubs and Aerials for Smart Meters have to be supplied via approved channels and can only be installed by authorised engineers. In fact attempting to install one yourself will trigger the tamper alarm on the meter which could mean a chargeable visit from your supplier. (Updated: 2021-11-16)
What is an Auxiliary load control switch (ALCS)?
Large domestic loads like storage heaters or heat pumps can be connected and controlled independently of the customer's main supply. An ALCS inside a smart meter can switch the electricity supply to the devices connected to it on or off based on an agreed switching pattern. It works in the same way as traditional Economy 7 meters, providing a scheduled period of power to connected devices. Subject to an agreement made between supplier and customer this could also support ad hoc commands allowing switches to respond to wider network conditions such as periods of excess renewable generation. (Updated: 2021-04-09)
Are the meters battery powered?
The electricity meter is mains powered but the gas meter is battery powered. The gas meter battery can be replaced by a Smart Meter Installer and is excepted to last the life of the meter (10 to 15 years), however, its life can be greatly reduced heavy communications such as repeated firmware updates. (Updated: 2016-01-27)
What is a SMETS1 meter?
Over 7 million electricity meters and a similar number of gas meters built to the first Smart Metering Equipment Technical Specification (SMETS) 1 have now been installed. These meters are better than ADM meters (Advanced Domestic Meters) but not as good as SMETS2 meters. Each supplier uses them through a different support and communications network; this means they have different functionality and effectively limits the customer from moving from one supplier to another with the same smart meter. For this reason customers often lose smart functionality when changing suppliers. Meters to the SMETS2 standard do not have this restriction as they share a common communication process. (Updated: 2018-05-05)
Do smart meters work with home generated renewable energy?
Traditional meters are only capable of recording consumption and consequently don't take into account any energy generated by a household. If you have or are planning to install solar panels or any other renewable energy generating system in your home, a smart meter will enable you to measure how much energy you produce. The smart meter will also calculate whether or not there is a surplus which you could sell back to the grid.
However, as this is not a common requirement suppliers have been slow in implementing systems to support it - you will have to shop around for the supplier which can support your requirements. (Updated: 2019-10-21)