Smart Meter Messages

Many commands can be sent to Smart Meters and many alerts received back. All of these are sent through a very secure closed network.

Security

Security has been considered very carefully for Smart Meters. The communications network is not part of the internet, it is a closed network only accessible to parties with the right security keys and physical connections. Additionally, there is no central database containing customers' information, the information is only stored on the Smart Meters and sent through DCC onto Suppliers and other parties who have a right to that data and where the customer has given them permission. The customer information inside messages is encrypted and only the receiving party can look at the data, the DCC cannot view the data. The parties receiving the data undergo a rigorous security assessment at the beginning and then have regular security audits.

The UK Product Security and Telecommunications Infrastructure (PSTI) Bill (2021) did not cover Smart Meters as they are already covered by robust regulation.

The National Cyber Security Centre has an excellent document explaining how the security works in relatively simple English.

Distribution Network

As well as Suppliers getting information from smart meters the Distribution Network Operators (DNOs), who look after the cables in the ground, will also get information. They can use this information to detect when cables might get too hot, the voltage drops in an area (known as a brownout) and when the power cuts out. The detailed information of performance over time can be used to help plan reinforcement of the network as demand increases.

Meter Alerts

Smart Meters can send information about the meter's environment and status as well as meter readings. This information can be used to diagnose meter faults, detect theft and security issues. There are some 250 events which can be sent in this way, suppliers and distributors will monitor these alerts, and take action at the appropriate point. For example, a memory alert may mean the meter is faulty, whereas a reverse flow alert could mean that someone has reversed the meter in order steal energy.

Alerts add a high volume of messages to the communications flows, for example in March 2024 some 2,123 million messages were sent and received in total.

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 is for devices such as meters and communication hubs, and has been taken from the Version 3.1 draft 4 of the DCC User Interface Specification (DUIS) added 10^th June 2019.

• 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)
• Read Device Configuration (Event and Alert Behaviours)
• 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
• Update Device Configuration (daily resetting of Tariff Block Counter Matrix)
• Update Device Configuration (RMS Voltage Counter Reset)
• Set CHF Sub GHz Configuration
• Request CHF Sub GHz Channel Scan
• Read CHF Sub GHz Configuration
• Read CHF Sub GHz Channel
• Read CHF Sub GHz Channel Log
• 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 number of messages from DCC rather than from the meters:

• 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
• Security Credentials Updated
• PPMID Removal
• Firmware Version Mismatch
• Dual Band CH Alert
• S1SP Alert DSP
• DUIS Version Mismatch
• Quarantined Request
• SMETS1 CH Firmware Notification
• ALCS HCALCS Configuration Change.