Electric Rule 21 interconnection by the California Public Utilities Commission mandates the interconnection standards for a select set of renewable generators. These interconnection requirements would require Inverters to support IEEE 2030.5 and need to connect to Utility SCADA Systems directly or through an Aggregator initially for monitoring purposes and later for control as well. The requirements also mandate compliance with cybersecurity requirements as specified by the SIWG and in the CSIP.

Rule 21 Low-Cost Telemetry Gateway

CA Rule 21 Gateway (SYNC2310 ) is SunSpec Certified IEEE 2030.5 Gateways. The DER gateway is used to interconnect Distributed Energy Resource (DER) site with the utility headend system, over IEEE 2030.5.

Gateways can communicate with the DER devices on-site, e.g., smart inverter or Energy Management System (EMS) using any of the communication interfaces defined in IEEE 1547-2018 (Modbus, DNP3, and IEEE 2030.5). Common Smart Inverter Profile (CSIP) certified IEEE 2030.5 aggregator client support in the gateway helps the utility to monitor and control any DER locations regardless of the communication capability of the field devices, thereby reducing overall interconnection costs.

DER Remote Site Gateways come with a comprehensive device management service through ASE/Kalkitech’s kalki.io device management solution. It provides a secure, centralized device management service. Kalki.io service can be used to update gateway firmware, security patches, license, and configuration files to the gateway. It also acts as a central repository for configuration, settings, and logs retrieved from the field gateways. Kalki.io can also be useful for continuous monitoring of events and alarms from the gateway and helps users to take necessary actions on time, thereby minimizing downtime and truck rolls.

Kalkitech remote device maintenance access service provides a role-based remote configuration and management access for field devices such as inverters, DER controllers, storage controllers, or meters by extending connectivity from the programming port of the field device with the engineering and configuration tool situated at a remote location over a public/ private network on a secured link.

  • SunSpec CSIP certified IEEE 2030.5 aggregator client used for utility integration
  • Field device integration supported over – Sunspec Modbus, DNP3.0 Serial and TCP, IEC61850
  • OPC UA, MQTT, IEC60870, DLMS, SNMP protocols supported
  • The device is secured from the ground up, including OS, kernel, and applications software, user permissions, firewalls
  • All software releases and patches are signed using manufacture specific PKI trust chains
  • Role-based remote management and device maintenance access managed and maintained by ASE/Kalkitech-Systems PKI infrastructure
  • Rule 21 PKI infrastructure approved by utility/regulator can be used for establishing IEEE2030.5 connection with utility DER Headend Server
  • Secured remote device access for field equipment maintenance and updates (e.g., Inverters or DER controller configuration)
  • Basic digital and analog logic programming supported. Enhanced programming based on IEC 61131-3 is available on request*

IEEE 2030.5 Aggregator Client Edge Gateway Software SyncConnect has ready-made templates to connect with standard inverters available in the market and also support for standard protocols such as IEEE2030.5, SunSpec Modbus, DNP3, and IEC61850-90-7 which helps the user to integrate any inverters, string combiners, weather sensors, battery controllers or meters seamlessly. It also supports commonly used utility protocols like IEC-60870, DNP3.0, DLMS-COSEM to connect with the grid operator. SyncConnect enables secure connectivity with each device remotely for configuration and maintenance purposes. SyncConnect runs in any standard Linux OS-based hardware/ Virtual Machines/ Containers.

IEEE 2030.5 Client Gateway can be deployed within an Inverter, in a Controller, or as a standalone gateway using any off-the-shelf hardware. With support for X.509 certificate, strong NERC/CIP compliance configuration support, support for TPM and TLS 1.2, this is ideal for a faster go-to-market. Given the support for IEEE 1547, IEEE 2030.5, and IEC protocols and security requirements together with integration capability with multiple devices, Kalki.io Edge is ideal for building a single unit that can be deployed not just for the Rule 21 market but worldwide.

More information on Kalki.io Edge Gateway Software is available here

IEEE 2030.5 Aggregator

Rule 21 Aggregator software based on kalki.io is a scalable SaaS / Cloud solution that supports IEEE 2030.5 Server and Client as well as OpenADR. Further, it supports SCADA / Utility protocols like DNP3, ICCP and OPC UA and REST/JSON APIs. The Aggregator will act as a Cloud Gateway for IEEE 2030.5 or DNP3 or Modbus devices, enabling many to many protocol conversion and data aggregation.

Depending on the agreement between the Utility and Aggregator or the Renewable Developer, the Aggregator software can be configured to the appropriate protocol or interface.

With strong PKI and X.509 infrastructure in the kalki.io aggregator platform, customers can install and integrate their own specific PKI system to kalki.io. Support for SunSpect mandated PKI system is easily possible.

The Aggregator provides remote monitoring and management of solar generation plants and their associated components by securely connecting with inverters, weather stations, irradiance sensors, revenue meters, and batteries as required for the deployment.



Supports multiple makes of inverters and revenue meters

Edge Storage and analytics to mitigate internet/ communication loss

User-friendly interface with single line diagram, dashboards, report & alerts

REST API and cloud/IoT platform connectors for building additional applications

Remote Device Management

Rule 21 implementation will result in a large number of small solar generators getting connected to the Utility Grid and communicating to the utility directly or through an Integrator. It is humanly impossible to manage, maintain and keep up to date these systems. Further cybersecurity audits and analyses of these systems also need to be done routinely. Kalki.io Remote Device Maintenance Access provides remote configuration and management access for field devices by securely extending the connectivity between the device’s programming port and engineering tool over a public/private network. Remote Device Access can also be used to acquire data from a device over a wide number of utilities, industry, and IoT protocols supported.

More details on Remote Device Access are available here


The secure on-demand connection between the device and a remote workstation for device configuration and troubleshooting

kalki.io acquire data from devices over 100+ industrial and utility-specific protocols

Role-based access control on-device data and configuration access

IEEE2030.5 Gateways for Smart Inverters

Rule 21 / CPUC regulations in California require all Smart Inverters to be compliant with IEEE 2030.5. This compliance can be met by directly implementing IEEE 2030.5 in the Smart Inverter or using an IEEE 2030.5 / CSIP Certified Gateway.

SYNC2000 Gateways are ideal for this requirement. They are rugged, compact, and secure hardware that supports IEEE 2030.5, SunSpec Modbus, DNP3, and IEC 61850. The SYNC 2101 family supports native Digital I/O and Analog Inputs with a comprehensive Logic Programming Engine based on IEC 61131. The SYNC 2101 controller can be used to communicate directly with Utility SCADA or head-end over native TLS 1.2 connections or over DNP3, both for monitoring and also to do control action.

With support for Cloud Connectivity to Azure, AWS, and IBM Cloud IoT infrastructure and generic MQTT support and support for kalkitech device management framework, SYNC2000 and SYNC 2101 are for complying with Rule 21 requirements.

Smart Inverter Embedded Modules

Convert Modbus, DNP3 to IEEE 2030.5 and MQTT for Utility, Aggregator & Cloud Interconnection

SYNC200 Embedded Modules are ideal for this requirement. They are rugged, compact, and secure hardware that supports IEEE 2030.5, SunSpec Modbus, DNP3, and IEC 61850 and can be integrated into your Smart Inverters. SYNC200 modules support APIs to build a proprietary interface to your Inverter Application.

Solution Components

  • IEEE 2030.5 Gateway Edge Software that supports Modbus, DNP3, IEC 61850, DLMS, and IEEE 2030.5 with X.509 support and Cyber security support
  • Edge Hardware that supports Modbus, DNP3, IEC 61850, DLMS, and IEEE 2030.5 with X.509 support and cyber security support. The hardware also comes with Digital I/O and Analog I/O to monitor hardwired inputs or take control action.
  • Aggregator Software that supports IEEE 2030.5 Server and Client, in addition to DNP3, SunSpec Modbus, IEC 61850, DLMS, etc., that can  integrate with renewable generators, batteries, etc., as well as Utility SCADA Systems over IEEE 2030.5 or other Utility SCADA Protocols
  • Remote device management with monitoring & control dashboards for managing and maintaining renewable generators and storage.

Data Collection

  • Real-time and historic data acquisition
  • Proven Interoperability with sensors, controllers, measurement devices, and protection relays
  • A large library of protocol support for standard and legacy protocols


  • TLS 1.2 based communication security
  • Secure role-based access control using X.509 PKI standard

Data Processing

  • Real-time streaming and data processing
  • User-configurable data processing
  • Event handling, and time-based data
  • ML and AI integration


  • Large deployment, monitoring, and management support
  • Scales with a large number of devices and data
  • Scales with edge device resources
  • Containerized services

Data Storage

  • Store data periodically or on an event basis
  • Time series database for optimal performance
  • Database management options


  • Remote configuration and settings
  • Over-the-air firmware and patches updates

Data Distribution

  • Amazon AWS
  • Azure
  • MQTT
  • OPC UA
  • Google Cloud


  • Deployable on your hardware and OS
  • Peer-to-peer data transfer capability
  • Choose the best bread hardware suitable for your application
  • Integrate with local/remote SCADA systems as well as cloud platforms

Smart Inverter Embedded Modules

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