GSM-AUTO 4G Wireless Remote Controller SIM installation guide

Which SIM does the GSM-AUTO 4G take?

A nano SIM (4FF), voice-capable, PIN lock off. Like the RTU relays it competes with, the GSM-AUTO opens gates on a rejected call — so it needs almost no credit, but the SIM must stay active, so check your network's PAYG inactivity rules.

Which network?

Any UK network with 4G at the controller. The GSM-AUTO usually lives in a weatherproof box by the gate or in the operator housing — steel enclosures kill signal, so plan the antenna outside the box. A multi-network SIM keeps the controller reachable on the strongest carrier, which for a dial-to-open device is the whole product.

Fitting the SIM

For the installing engineer, power off:

1. Fit the nano SIM in the holder on the board.
2. Antenna on before power — and routed outside any metal enclosure.
3. Wire the relay output to the operator's trigger input; match pulse or latch mode to what the operator expects.

First power-up

Let it register, then configure by SMS per the manual: admin password first, then whitelist numbers in full international format (44…, not 07…). Test: call from a whitelisted phone — it should ring off unanswered and the relay should click.

If it won't open

• Rings but no relay: the caller's number isn't matching — re-add in international format.
• Call won't connect at all: unit off network. Signal at the enclosure, SIM active, antenna outside the box.
• Relay fires, gate ignores it: operator-side wiring or pulse/latch mismatch.

FAQ

Why is calling it free? It rejects the call before answering — no connection, no charge.

AC or DC version — same SIM? Yes, the SIM guidance is identical.

Will it outlast the switch-offs? Yes — it's 4G hardware, which is its advantage over the 2G RTU units it replaces.