IoT Gateway
SIM Connectivity (GW-1, GW-2)
Installing a SIM card, configuring mobile data APN settings, and understanding SIM failover on compatible gateway models.
How SIM Connectivity Works
The GW-1 and GW-2 gateways include a nano-SIM slot for 4G/LTE cellular data connectivity. The SIM connection operates as an automatic fallback — Wi-Fi is always the preferred uplink, and cellular data activates only when Wi-Fi is unavailable for more than 60 seconds. This ensures uninterrupted monitoring on remote sites, agricultural deployments, and locations where broadband connectivity is unreliable. Data collected during SIM operation is synchronised to the HPzenAi cloud when Wi-Fi is restored.
Supported SIM Types
The GW-1 and GW-2 accept a standard nano-SIM (4FF form factor). Use a SIM card with an active data plan from any mobile carrier with data coverage at your installation site. Pre-paid and post-paid plans are both supported. An eSIM profile can also be provisioned via the app for supported carriers on request from HPzenAi support.
Steps
- SIM type: nano-SIM (4FF), standard plastic card.
- Supported networks: 4G LTE (primary), 3G WCDMA (fallback).
- Data plan: any carrier with coverage at the installation site.
- Roaming SIMs are supported — confirm your carrier's data roaming plan includes the installation region.
- Minimum recommended data allowance: 100 MB per month per gateway for typical field device polling intervals.
Installing the SIM Card
Always power off the gateway before handling the SIM card. Installing or removing the SIM while powered on can damage the SIM slot or corrupt the SIM profile.
Steps
- Power off the gateway by disconnecting the 12V DC supply.
- Open the SIM slot cover on the side panel of the gateway.
- Insert the nano-SIM card with gold contacts facing down and the notch corner first.
- Push the SIM gently until it clicks into the locked position.
- Close the SIM slot cover until it clicks shut.
- Reconnect the 12V DC supply and power the gateway back on.
Configuring APN Settings
Many mobile carriers are detected automatically by the gateway — the APN is populated from the SIM card data. If automatic detection fails (the SIM LED flashes amber but never turns solid), enter the APN settings manually.
Guided Help Center
Open the HPzenAi app.
SIM Status LED Indicators
Monitor the gateway LED to understand the current SIM and connectivity state.
| LED State | Meaning |
|---|---|
| Solid green | Wi-Fi is active and connected to the HPzenAi cloud |
| Solid amber | SIM / mobile data is the active uplink — Wi-Fi is unavailable |
| Flashing amber | SIM is connecting or searching for a mobile network |
| Flashing blue | Gateway is in Wi-Fi setup mode — no Wi-Fi or SIM active |
| Flashing red | Authentication error — incorrect Wi-Fi password or SIM APN |
| No LED | Gateway has no power — check the 12V DC supply |
SIM Data Usage and Management
Monitor SIM data consumption from the app to avoid overage charges. Go to Device Settings → Network → Mobile Data → Usage to view the current monthly data usage. You can set a data usage alert threshold to receive a push notification before your plan limit is reached.