# Open Your Gate With Your Phone: GSM Relay Setup in 7 Steps

> Open your gate with your phone in 7 steps: wire a GSM relay to the motor's push-button input, add your number by SMS, then call or tap to open.

Canonical: https://gate-opener.app/blog/open-gate-with-phone-gsm-relay/
Last updated: 2026-11-03

To open your gate with your phone, wire a GSM relay module to the push-button input of your gate motor, put in a SIM card, and text the module your phone number. Calling the module's number then opens the gate. This guide covers the seven steps for any module, with the commands for RTU5024 and Callny.

Your gate has a remote, and the remote is never where you need it. A GSM relay fixes that for the cost of a small module and a SIM card: you call a number, the gate opens. This guide takes you from a bare gate motor to opening it with your phone, whichever module you buy.

## What Do You Need to Open a Gate With Your Phone?

A GSM relay is a small module with a SIM card slot and a relay output that opens your gate when an authorized phone number calls it. It talks to your phone over the ordinary mobile network, so it needs no Wi-Fi, no internet and no app on the gate side. The relay output takes the place of a push button on your gate motor's control board.

You need four things:

- An automatic gate whose motor has an input for an external push button or key switch.
- A GSM relay module, such as the [RTU5024](https://gate-opener.app/hardware/rtu5024/) or the [Callny G202 PLUS](https://gate-opener.app/hardware/callny-g202/).
- A SIM card that can make calls and receive SMS, with mobile signal at the gate.
- A low-voltage DC supply for the module. Many motor boards have an accessory output you can use; check its voltage first.

If you want to know what happens inside the module during a call, read [how a GSM gate opener works](https://gate-opener.app/blog/how-gsm-gate-opener-works/).

## How to Open Your Gate With Your Phone, Step by Step

The steps are the same for every GSM relay. Only the text of the SMS commands differs between modules, so each command below is shown for the two most common families: the RTU5024 and the Callny G202 PLUS / G203. The password in the examples is the factory default, 1234.

### 1. Find the push-button input on your gate motor

Switch off the gate's mains power, then open the cover of the motor's control board. Look for the terminals an external push button or key switch connects to. Common labels are START, PP (step by step), OPEN, K or STEP, usually next to a COM or GND terminal. The board's manual shows which pair it is. If you briefly bridge those two terminals with a wire while the power is on, the gate should start to move. That pair is where the GSM relay goes.

### 2. Pick a GSM relay module

Any module with a dry-contact relay output works. The RTU5024 is the most common; the Callny G202 PLUS is sold under several brand names. Both come in 2G and 4G versions. Operators are switching off 2G in many countries, so check the [2G shutdown dates for your country](https://gate-opener.app/blog/2g-shutdown-dates-by-country/) and read [RTU5024 4G vs 2G](https://gate-opener.app/blog/rtu5024-4g-vs-2g/) before you buy. If the module already sits on your gate and you don't know which family it is, compare the two in [Callny G202 vs RTU5024](https://gate-opener.app/blog/g202-vs-rtu5024/).

### 3. Prepare the SIM card

Put the SIM in an ordinary phone first. Turn off the PIN code lock, make one call and send one SMS to check both work, and write down the SIM's phone number: that is the number you will call to open the gate. Check the SIM size your module takes. A prepaid SIM works, but it must stay active. See [which SIM card to use in a GSM gate opener](https://gate-opener.app/blog/best-sim-card-gsm-gate-opener/).

### 4. Wire the relay to the push-button input

With all power off, run two wires from the module's relay terminals marked COM and NO (normally open) to the push-button pair you found in step 1. Connect them in parallel with any button that is already there, so the old button keeps working. The relay only closes a contact, like a finger on a button. Never put the motor's mains power through it.

Power the module from a DC supply within its rated range. According to the [RTU5024 product page](https://bliiot.com/products/gsm-3g-4g-gate-opener-1-relay,-dial-to-open-the-gate-rtu5024) and the [G202 manual](https://www.manualslib.com/manual/2166631/Gsm-G202.html), both modules take a DC input; read the exact range on your unit's label before you connect it. Put the SIM in, mount the antenna outside any metal box, and switch on. Wait until the module has registered on the network. According to the [G202 PLUS / G203 user manual](https://manuals.plus/ae/1005004664477430), its signal light flashes once per second while it registers and once every 2 seconds when registration has succeeded. For other modules, check the LED table in the manual.

### 5. Add your phone number

The module only opens for numbers on its list, so the first SMS you send adds your own. Write the number with 00 and the country code (0031612345678 for +31 6 12345678): the RTU5024 command reference says to use 00 instead of +, and the G202 manual writes UK numbers as 0044. Both examples below put the number in user slot 001. On a Callny module the first number added becomes the super admin. On an RTU5024, first tell the module its own SIM number with `{pwd}TEL{moduleSIM}#`, for example `1234TEL0031687654321#` (see the [RTU5024 setup guide](https://gate-opener.app/blog/rtu5024-setup-guide/)).

RTU5024: `{pwd}A{slot}#{phone}#`

`1234A001#0031612345678#`

Callny G202 PLUS / G203: `{pwd}#TEL{phone}#{userID}#`

`1234#TEL0031612345678#001#`

The module confirms by SMS. No reply usually means a typo, no signal or no credit on the gate SIM. Module by module: [add a number to an RTU5024](https://gate-opener.app/blog/how-to-add-phone-number-rtu5024/), [Callny G202 setup guide](https://gate-opener.app/blog/callny-g202-setup-guide/).

### 6. Lock it down

The RTU5024 and the Callny G202 PLUS both ship with the default password 1234, and anyone who knows the gate's number and that password can text it commands. Change it now, then make sure the module only opens for numbers on its list.

RTU5024: `{pwd}P{newpwd}`

`1234P6666`

Callny G202 PLUS / G203: `{pwd}#PWD{newpwd}#PWD{newpwd}#`

`1234#PWD5678#PWD5678#`

RTU5024: `{pwd}AUT#`

`1234AUT#`

Callny G202 PLUS / G203: `{pwd}#AU#`

`1234#AU#`

The first two lines change the password (to 6666 and 5678 in these examples); the last two switch the module to authorized numbers only. From now on, use your new password in place of 1234.

### 7. Call to open

Call the gate SIM's number from your phone. The module sees your number, hangs up and closes the relay for a moment, and the motor treats that as a button press. You can also open by SMS:

RTU5024: `{pwd}CC`

`1234CC`

Callny G202 PLUS / G203: `{pwd}#ON#`

`1234#ON#`

If the gate does not move, see the next section. If it moves, save the gate's number as a contact or put a one-tap shortcut on your home screen.

## Why Doesn't the Gate Open When I Call?

When a call to a GSM relay does not open the gate, the cause is almost always one of four things: the call does not reach the module, the module does not recognize your number, the relay is wired to the wrong input, or the pulse is too short for the motor. Work through them in this order.

### The call rings out or you hear "not available"

The module has no signal, no credit, or a SIM with its PIN lock still on. Check the network LED, move the antenna out of any metal enclosure, and test the SIM in a phone again.

### The module hangs up but the relay does not click

Your number is not on the list, or it is stored in a different format from the one your phone sends as caller ID. Add it again with 00 and the country code, as in step 5.

### The relay clicks but the gate does not move

The wires sit on the wrong terminals, or on NC (normally closed) instead of NO. Bridge the push-button pair by hand to prove the input works, then move the relay wires there.

### The gate twitches but stops

The motor needs a longer press. Raise the relay time with the GOT command; the [RTU5024 troubleshooting guide](https://gate-opener.app/blog/rtu5024-troubleshooting/) and the [Callny G202 command reference](https://gate-opener.app/hardware/callny-g202/commands/) give the syntax for each module.

## Opening the Gate With an App Instead of a Call

A gate opener app drives the same GSM relay. It makes the same call or sends the same SMS you would, from your own phone and your own SIM, so it works where your phone has signal and needs no internet. It saves you the typing, with no command syntax to look up, no password to put in front of every text, no slot numbers to remember.

Everything in steps 5 to 7 is a button in GateOpener. You pick your module, and the app writes the add-user, password and access commands in that module's syntax and reads the replies back to you:

- One Open Gate button per gate, and a home-screen widget
- Add family, guests and contractors from your contacts
- RTU5024, Callny and 30+ more modules in one app
- One-time purchase, no subscription, no account, no cloud

[Open your gate from your phone](https://gate-opener.app/download/)

## Frequently Asked Questions

### Can I open my gate with my phone without Wi-Fi?

Yes. A GSM relay works on the mobile network, so it needs signal where the gate is, not Wi-Fi or internet. Your phone calls the SIM card in the module and the module switches the gate.

### Does it cost anything each time I open the gate?

The G202 PLUS / G203 user manual describes opening by call as free calling: the module hangs up instead of answering. Whether your own plan charges for an unanswered call is up to your operator. The SIM in the module still needs to stay active, and SMS commands cost what your plan charges for a text.

### Will a GSM relay work with my gate motor?

It works with any motor whose control board has an input for a push button or key switch. The relay acts as that button. It does not switch the motor's mains power, so the brand of motor matters less than having that input.

### Can other people open the gate with their phones?

Yes. Add each phone number to the module's list of authorized numbers with the add-user command, or in the GateOpener app. Each person then opens the gate by calling the same module.

## Sources

### Manufacturer Documentation

- [RTU5024 GSM gate opener, product page (BLIIoT)](https://bliiot.com/products/gsm-3g-4g-gate-opener-1-relay,-dial-to-open-the-gate-rtu5024)
- [GSM G202 user manual (ManualsLib)](https://www.manualslib.com/manual/2166631/Gsm-G202.html)
- [G202 PLUS / G203 user manual (manuals.plus)](https://manuals.plus/ae/1005004664477430)
- [RTU5024 SMS command reference](https://gate-opener.app/hardware/rtu5024/commands/)
- [Callny G202 PLUS SMS command reference](https://gate-opener.app/hardware/callny-g202/commands/)

### Related Guides

- [How a GSM gate opener works](https://gate-opener.app/blog/how-gsm-gate-opener-works/)
- [RTU5024 setup guide](https://gate-opener.app/blog/rtu5024-setup-guide/)
- [Callny G202 setup guide](https://gate-opener.app/blog/callny-g202-setup-guide/)
- [Best SIM card for a GSM gate opener](https://gate-opener.app/blog/best-sim-card-gsm-gate-opener/)

## Related
- [How Does a GSM Gate Opener Work? A Simple Explanation](https://gate-opener.app/blog/how-gsm-gate-opener-works/)
- [How to Set Up Your RTU5024 GSM Gate Opener](https://gate-opener.app/blog/rtu5024-setup-guide/)
- [Callny G202 PLUS Setup Guide: SMS Commands and Configuration](https://gate-opener.app/blog/callny-g202-setup-guide/)