The unit will not power up.
Make sure the wires from the power supply are wired correctly. The wire with the white stripe must go to the + terminal. Watch the following video to view normal startup status indicators.
The unit powers up but there is a beeping coming from the intercom.
This means that the unit is not able to detect the network for some reason (see the video above for the normal way it should power up).
- Make sure the SIM card is properly locked in and seated as shown in the pictures below.
- If you just purchased a SIM card, it will not be "locked" to another device, but you must call, go online, or otherwise activate the SIM card per the carrier's instructions or it will not function.
- Make sure the SIM card is not "locked" to the cell phone you took it out of. Do this by calling the service provider and telling them you need the SIM card unlocked because you are using it in a different device.
- Remove the SIM card and place it in a phone to see if it is activated and has minutes available on it. Make a test phone call to and from the phone.
- Make sure the SIM card does not ask for a PIN code when it is in a phone. If it does, make sure you disable this.
- Make sure the SIM card is not 4G as this intercom only works with 2G or 3G SIMs. It also must be a T-Mobile or AT&T SIM. This unit will not work with Verizon or Sprint services.
- Check that the cable from power supply to intercom is less than 15 feet and that the cable thickness is 14 gauge. Alarm, CAT5 or thin gauge cable is not sufficient.
- Check the reception on your cell phone. If there is a low quality signal on it, see the "Low Reception" section.


I enter the text messaging codes but I keep getting an error message or constant beeping.
- You cannot enter codes from the keypad on the unit. You must send them via text messaging from your cell phone or using a free text messaging service on your PC.
- Make sure you are entering all the code including the trailing # character. Without the trailing # code you will see the information you entered followed by "error".
- If you have a keypad version of the intercom, you CANNOT program the GSM module using the keypad. You must use text messaging from your cell phone, or from a free text messaging service you can find on the internet by searching for "free text messaging".
My cellphone service requires an IMEI number.
If the cell phone service provider you sign up requests an "IMEI number" from your device, it is located on the cellular modem within the control unit as shown in the picture to the right. If you purchase a phone to go with the service, use the IMEI number of the intercom control unit instead of the phone you are signing up.
The party on the phone can't hear anything transmitted by microphone.
For units with a separate speech panel and control module, check the wiring of the microphone to make sure the + terminal on the speech panel is connected to the + terminal of the control module. If the polarity is reversed, the microphone will not work.
The party on the phone hears very poor or low audio.
- Too long of cable between speech panel and gsm unit causing signal loss. The cable should be less than 26 feet--the shorter the better.
- Not using shielded cable or shield not grounded causing interference levels to increase. Make sure the wire from the shield is connected to the "- out" terminal on the control module. The shield wire on the speech panel side does not need to be connected at all, but just make sure it isn't touching any electronic component. You can also connect it to the metal housing if you want.
- Low reception. Send a *20# text message to the unit and verify that the signal level is at least 10 (the number will read between 1-31). If the signal is below 10, see the "Low Reception" section.
- Bad or weak terminal connection. Check all connections to make sure they are properly wired.
- Antenna position too low and needs raised above the level of the speech panel.
The star key is not working to open the door or gate.
- Reception is poor so the signal quality is below par meaning the analog tone cannot be heard very well by the intercom. Send a *20# text message to the unit and verify that the signal level is at least 10 (the number will read between 1-31). If the signal is below 10, see the "Low Reception" section.
- The most common reason is that they have previously pressed # by mistake. This latches the relay permanently. It can be unlatched by SMS and also simply by pressing the 1 key next time the intercom calls you.
- People who have iPhone 5 are having issues as well. Apple must have shortened the DTMF timing on the * key so we recommend reprogramming it to #. You can move keys around then using this procedure:
*12*1234#61?# This will change the momentary trigger from star to another key. Replace ? with the key you want.
*12*1234#63?# This will change the latching key from hash to another key. Replace ? with the key you want.
*12*1234#64?# This will change the release key from 1 to another key. Replace ? with the key you want.
The unit calls the first number but voicemail comes on before it can ring the second number.
- Increase the "no answer" time as per the programming instructions.
The caller ID feature does not work to open the door or gate.
- Be sure to follow the programming instructions for the *12*1234#72# SMS code listed in the programming instructions. If your calling line ID is blocked or not listed, then this feature will not work. Even if you have already programmed a number to receive a call when the button is pressed. You still have to program the number into the unit using this 72 feature.
- Ensure the number is entered as you would normally dial it from another phone. You MAY need to enter a 1 before the number. Some areas of the U.S. require a 1 and some don't.
- Make sure you enter the country code using the *12*1234#71# SMS code. The country code for the U.S. is 1.
- International calls ringing the unit may not work.
There is no audio from the gate, but the person at the gate can hear OK.
This can be due to low reception.
- Check the reception level by texting *20# to the unit.
- Change SIM card to another network with better coverage if necessary
- Incorrect microphone wiring could be the problem. Make sure the polarity of the wiring is correct: positive (+) to positive (+) and negative (-) to negative (-).
- Check for short circuits between the wires. If strands of the wiring are touching each other, this will cause a short circuit.
- See "Low Reception" section for more ideas.
The audio quality heard on the remote telephone is poor or humming (buzzing).

- This intercom uses technology called GSM which can produce a small amount of buzz, but it should not produce so much that causes inability to hear the person speaking. This can be caused by the antenna being being mounted too close to the speech panel or not being mounted high enough. The antenna should be higher than the speech panel.
- Make sure the ground wire on the shield is connected to the negative side of the 12V OUT terminal as show in the picture to the right. The ground wire on the speech panel side can also be tied to the metal housing of the speech panel.
- This is a symptom of poor reception. See the "Low Reception" section for more details on how to fix this.
The * or # key does not work when the intercom calls a phone
- Try pressing the buttons longer when attempting to activate the door or gate (if you are using a cell phone this may not work. Program in a landline phone to see if that solves the problem.
- Check if you can hear the relay clicking at the gate when the * or # key is pressed during a call. If it can be heard, then the system is working.
- Check the wiring between the lock or and panel. If the relays not not make a clicking sound, then check this feature on a different mobile call phone or land-line.
- Failure of the unit to receive the tones can be a symptom of low reception. See the section on "Low Reception" for details on how to fix this.
Low Reception
- If the signal is low the electronics of the control module will attempt to boost its antenna power, however, too much of this antenna boost can cause interference. Try mounting the unit higher or get an external GSM antenna that works with the 850/1700/1900 MHz bands, with 3dB or more of gain. The connection is a SMA male type. Regardless, for best reception, the antenna/Control module should be mounted higher than the speech panel. With wireless signals, a few feet of antenna height can make a huge difference.
You also need to be aware of any objects around that could be blocking the signal such as metal or shrubbery. The cell phone signal falls into the UHF range with a wave width of about a foot and a half wide. So if a metal gate has bars closer than a foot and a half apart, the wireless signal can be blocked if it has to travel through it. Your microwave oven provides an example of this. The glass front door has a metal mesh with very small holes. Microwaves being an extremely high frequency have wavelengths that are only several inches long. The mesh keeps the microwaves trapped in the oven but it allows you to see inside because light waves have a microscopic wavelength as illustrated in the diagram.
- Check the antenna connection thoroughly. Remove the antenna and look to see if the center pin inside the antenna is intact and has not been pushed back inside the fitting.
- Try removing the existing antenna and installing an external high-gain antenna as high as possible.
- Another solution is to switch to a different cell phone provider to see if they have better reception.
Intermittent Reception
If while texting *20# to the unit you get readings that include the letters WCDMA one time and then the next time it just shows the network name and signal level, this means the unit is switching between 2G and 3G service. WCDMA is 3G service. This erratic behavior means there is a weak 3G signal level coming from the carrier and it will likely cause the intercom to malfunction. If your find your system locked up and making a beeping noise this could be the cause. If you have your gate latched open and it suddenly closes, this is likely the problem.
The solution is either to try the things in the Low Reception area above, switch to an antenna with higher gain, or preferably change to a carrier with a stronger signal.
Latched gate is closing by itself.
See Intermittent Reception section above.
Sound level on receiving telephone is very low
If the signal levels received by the intercom are very low, the intercom will attempt to boost the transmit output power by a factor of up to 200 times to maintain a good connection. The intercom's microphone is very sensitive so this boost in output power from the antenna can overwhelm the noise filters within the intercom. You can try connecting the metal chassis of the intercom panel to 0v (-) of the power supply, which may help with noise reduction and improve the audio. Also, see the Low Reception section for other details on how to handle this.
Forgot the programming password on the Cell Phone Board
If the programming password has been changed by accident, you cannot change it again unless you know the new code. The only way to set a new one is to do a hard reset, which will restore all defaults:
- Power off the device
- Make a link between one side of the push button and the OUT (-) of the power connection
- Power the unit on
- Press the S1 reset button on the circuit board
- Power the unit off and remove the link.
- Defaults should be restored
Forgot the programming password on the keypad
To default the keypad back to factory we need to :
- power down the unit for one minute.
- power up unit and short out the egress and com + contacts
- press 8080**
- press 01 0000 #
- press ** to get out of programming
At this point all the info has been re-set back to factory.
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