Hermetry accepts data in several ways. Every way ends in the same place: a device in your Devices list, with its telemetry, attributes, alarms and dashboards. Which way fits depends on what the device can do: whether it can keep a connection open, whether it speaks LoRaWAN, whether it sits behind another box, or whether it can only be asked. This page helps you choose.
Quick decision
| Your device… | Use | Start here |
|---|---|---|
| can keep a TCP connection open and has TLS (a controller, an industrial PC, a microcontroller board with Wi-Fi or cellular) | MQTT over TLS | MQTT |
| wakes up, sends and sleeps, or sits on a network that blocks MQTT | HTTPS device API | Device HTTP API |
| is a battery LoRaWAN sensor (EU868) | LoRaWAN, through a LoRaWAN gateway | Connect your first LoRaWAN sensor |
| speaks Modbus, RS485 or another field bus, or BLE, behind a router or gateway that reports for it | Behind a gateway | Devices behind a gateway |
| cannot dial out at all but answers SNMP (a UPS, a switch, a printer, a server) | Polled by the platform (Network device) | Polling devices over SNMP |
| is an IP camera or a recorder | Camera or recorder (polled, live view) | Add a camera or recorder |
| is a licensed router, gateway or controller made for Hermetry | Claim it with the code on its Cloud page | Adding and claiming devices |
All of these start from Devices > New device. The drawer offers one choice per way that your organisation has, and Other device for MQTT and HTTP devices.
Compare the ways
| MQTT | HTTPS | LoRaWAN | Behind a gateway | Polled | Licensed device | |
|---|---|---|---|---|---|---|
| Device opens the connection | Yes | Yes, per message | Through its LoRaWAN gateway | The gateway does | No: the platform asks | Yes (MQTT) |
| Login | Token, MQTT basic or X.509 | Token (bearer header) | Keys (OTAA or ABP) on the radio; no platform login | The gateway’s own login | Credentials of the box, stored write-only | X.509 certificate |
| Online status | Live connection, recent message or last seen | Recent message or last seen | Recent message (built-in profile) | From the gateway’s connect and disconnect messages | Last seen only | Live connection |
| Commands to the device | Yes | Yes (long poll) | Raw downlinks | In development | No | Yes, plus remote settings and remote access |
| Firmware over the air | Yes, if the firmware supports it | No | No | No | No | Yes |
| Counts toward the device limit | Each device | Each device | Each gateway and each sensor | The gateway and each child | Each polled device | Each device |
MQTT
The default and the most capable way. The device keeps one connection open, publishes telemetry and attributes, and receives commands and shared-attribute changes at once. Use TLS on port 8883. Plain MQTT on port 1883 is refused unless a profile allows it for devices that cannot do TLS.
Existing firmware that uses v1/devices/me/telemetry topics can keep them with the Legacy compatible topic scheme, and firmware with its own topic names can use Custom topics. See Device profiles.
HTTPS
Each message is one POST with the device’s token in the Authorization: Bearer header. Good for battery devices and restrictive networks. A device can also wait for commands with a long poll. Devices that cannot send headers can put the token in the URL, at the cost of losing MQTT and commands for their profile.
LoRaWAN
Hermetry has its own LoRaWAN network server for EU868, with OTAA and ABP activation, Class A and Class C. You register gateways (Basics Station gateways or licensed routers) and sensors; a codec turns each frame into readings. See LoRaWAN.
Behind a gateway
A gateway logs in as itself and reports for its child devices with the v1/gw/* topics. Hermetry creates each child the first time the gateway reports it. Up to 500 children per gateway by default.
In development: Sending commands and shared-attribute changes to devices behind a gateway is in development. Today the gateway reports for its children; plan commands to the gateway itself. See Commands to devices behind a gateway.
Polled by the platform
Some boxes cannot dial in. Hermetry reaches them instead through an endpoint: the box’s public address, its settings and its write-only secrets. Two kinds are available:
- Network device: an SNMP agent (v3, or v2c when switched on) that the platform polls on an interval with a template (for example UPS, network interfaces, host resources, printers).
- Camera or recorder: an IP camera or a recorder, for live view.
The box must have a public address, and your firewall must let the platform’s poller addresses in. Each poll result counts as one message. See Protocol endpoints.
Licensed devices
Licensed routers, gateways and controllers made for Hermetry come with a factory identity and certificate. You claim them with the code on their local Cloud page; they then connect with their certificate and offer remote settings, firmware updates and, for routers, remote access to their web panel. A licensed router can also be a LoRaWAN gateway and a gateway for field devices. See Licensed devices.
Questions that decide
- Does the device have a real clock? If not, let Hermetry stamp the time (send without
ts). Never invent time stamps. - Must you send it commands? Then use MQTT (or HTTPS long poll), not a polled or gateway child device.
- Is it on a mobile link? MQTT with batched messages costs least. Firmware updates over metered links wait by default.
- Can it do TLS? If not, give it a separate profile that allows plain MQTT and pin its networks. See Device transport security.
- How many of the same kind? Put them on one profile, and add them by bulk import, by self-provisioning, or for LoRaWAN by pairing mode.