Protocols and data

BACnet, OPC UA, MQTT, IEC 60870 and IEC 61850, SCADA, wireless networks and data quality.

A reading is useful only when it arrives with the right time, unit and quality. These guides cover the protocols that carry it (BACnet, OPC UA, MQTT, IEC 60870 and IEC 61850) and how to keep the data trustworthy through outages.

Start with SCADA architecture for the big picture, or BACnet vs Modbus for building projects.

Networks and architecture

8 guides · about 93 minutes

  1. Zigbee vs LoRaWAN for energy monitoring: when to use each Choose Zigbee, LoRaWAN or both for energy monitoring. Compare reporting needs, coverage, device classes and the integration work needed before deployment. 13 min
  2. What is SCADA? Architecture and energy use cases SCADA for energy sites: local control, WAN failure, protocol security, command evidence, outage recovery and a commissioning checklist. 16 min
  3. Cloud API vs local gateway for energy sites Compare cloud APIs and local gateways for energy data: call quotas, timestamps, outages, control, security and hybrid sites. 9 min
  4. Over-the-air firmware updates for IoT devices Plan Zigbee OTA and LoRaWAN FUOTA updates: delivery time, image signing, failure modes, campaign checks and field verification. 10 min
  5. IoT interoperability in multi-vendor systems Test multi-vendor IoT systems: protocol roles, register decoding, units, time, quality, security, recovery and a twelve-step acceptance check. 22 min
  6. IoT data privacy and GDPR compliance When meter and sensor data becomes personal data under the GDPR, and what that changes in the design, retention and export of an energy monitoring system. 10 min
  7. How to set a static IP address on Windows 11 Give a Windows 11 laptop a fixed IPv4 address to reach a ZGW-20 management port, check the link, open Edge and restore DHCP afterwards. 6 min
  8. How to set a static IP address on Ubuntu Desktop Use a second NetworkManager profile on Ubuntu Desktop for fixed IPv4, ZGW-20 management access and Edge; then restore the normal network. 7 min

BACnet and building protocols

7 guides · about 55 minutes

  1. BACnet vs Modbus for building integration Compare BACnet and Modbus for buildings: data models, networks, discovery, units, control priority, security and gateways between protocols. 10 min
  2. BACnet/IP vs MS/TP Compare BACnet/IP and MS/TP: speed, APDU size, token passing, bus capacity, faults, routing and reading existing controllers in a retrofit. 9 min
  3. BACnet objects, properties and point lists Build a BACnet point list: analog, binary and multi-state objects, Present_Value, Units, Status_Flags and the PICS. 6 min
  4. BACnet device instances, addresses and discovery BACnet discovery with Who-Is and I-Am: device instances, network numbers, MAC addresses and diagnosis when a device does not appear. 5 min
  5. BACnet routing, BBMDs and foreign devices BACnet across networks: routers, network numbers, BBMD broadcast tables, foreign device registration and discovery across IP subnets. 13 min
  6. BACnet COV vs polling, and data freshness Compare BACnet COV subscriptions and polling: change increments, subscription lifetimes, network load and checks for stale values. 8 min
  7. BACnet priority arrays and relinquish BACnet command priorities: the 16 slots, releasing commands with NULL, Relinquish_Default and testing writes without leaving an override. 4 min

OPC UA and MQTT

5 guides · about 49 minutes

  1. OPC UA vs MQTT vs Modbus Compare OPC UA, MQTT and Modbus: data models, status, timestamps, security, ports, one meter reading across all three and commissioning failure tests. 10 min
  2. MQTT QoS, retained messages and stale data MQTT QoS 0, 1 and 2: acknowledgements, retained messages, persistent sessions, last will, message expiry and checks for stale telemetry. 9 min
  3. What is MQTTS? MQTT over TLS for energy IoT Understand MQTT over TLS: certificates, broker identity, topic access, QoS limits and commissioning checks for trustworthy energy IoT data. 13 min
  4. OPC UA clients, servers and node identity OPC UA data identity: clients, servers, endpoints, security, NodeIds, namespace indexes, status, timestamps and point checks after a restart. 5 min
  5. OPC DA vs OPC UA: differences and migration Compare OPC DA (OPC Classic) and OPC UA: three migration paths, item-to-node mapping, preserving quality and timestamps, and cutover tests. 12 min

IEC 60870 and IEC 61850

6 guides · about 54 minutes

  1. Choosing grid communications: IEC 101, IEC 104 and IEC 61850 Compare telecontrol, MMS, GOOSE and sampled values for RTUs, solar plants, batteries and switchgear. Define the point list and acceptance tests. 6 min
  2. IEC 60870-5-101 vs IEC 60870-5-104 Compare IEC 101 serial polling and IEC 104 on TCP port 2404: k, w, t0–t3, field sizes, time tags, point encodings, tunnels and converters. 11 min
  3. IEC 60870 ASDUs, causes of transmission and addresses Read IEC 101/104 point lists: type identification, cause of transmission, common and information object addresses, plus an IEC 104 frame decode. 10 min
  4. IEC 60870 timestamps and quality descriptors IEC 101/104 time and quality: CP56Time2a, invalid and summer-time bits, plus overflow, blocked, substituted, not topical and invalid quality flags. 5 min
  5. IEC 60870 commands, select-before-operate and confirmation IEC 101/104 commands: direct execute, select-before-operate, activation confirmation, termination, qualifiers and checks of the real equipment state. 10 min
  6. IEC 61850: data models, MMS, GOOSE and SCL IEC 61850: logical devices and nodes, MMS reporting, GOOSE, sampled values, SCL files (ICD, SCD, CID) and comparison with IEC 60870-5-104. 12 min

Data quality and delivery

6 guides · about 58 minutes

  1. IoT sensor data: timestamps, quality and gaps Define IoT sensor data: point identity, units, source timestamps, quality, stale limits, counter rollover, outages and commissioning tests. 14 min
  2. Telemetry timestamps, source time and arrival time Sensor timestamps: source, collection and arrival time, interval labels, time zones, clock sync, late data and duplicates in energy telemetry. 4 min
  3. Stale, missing and invalid telemetry Distinguish stale, missing, invalid and estimated sensor readings, display their status, and handle their effects on totals, charts and alarms. 11 min
  4. IoT data storage: architecture and options Compare IoT databases, edge history, replay queues and cloud archives. Size storage, define retention and verify delivery and recovery before deployment. 14 min
  5. Store-and-forward buffer sizing for edge gateways Size a gateway buffer: record rate, outage duration, bytes per record, drain time after recovery, retention limits and full-queue behaviour. 5 min
  6. Industrial polling, backpressure and retries How to budget polling on an RS-485 bus or a Modbus TCP gateway: transactions per cycle, the cost of an offline device, overdue reads and safe retries. 10 min

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