Troubleshooting – SMS Lite

Please click the tab below for a comprehensive troubleshooting guide for the SMS Lite.

SMS Lite Troubleshooting

The SMS Lite has a status LED, labelled ‘Link’ located next to the antenna connection.

The SMS Lite status LED indicates these error codes to help identify issues:


Error Code – 2 Flashes – indicates the Modem will not power up.
This error code requires the SMS Lite be returned to QTech for service.


Error Code – 3 Flashes – indicates the Modem will not respond to commands.
This error code requires the SMS Lite be returned to QTech for service.


Error Code – 4 Flashes – indicates the SIM card is not inserted.
This error code may be fixed by checking the SIM card inside the SMS Lite.


Error Code – 5 Flashes – indicates the SMS Lite is not registered to the cellular network.
Normally caused by a weak cellular signal and may be fixed by using a higher gain antenna.


Error Code – 6 Flashes – indicates the cellular operator is not supported by the SMS Lite.
This error code may occur in some overseas locations.


Error Code – 7 Flashes – indicates the SIM card is currently busy.
This can occur briefly during the initialisation phase after the SMS Lite is powered up.
This error code may occur if the SIM card is not compatible with the SMS Lite.


Network Error Code – 3 Slow Flashes – an error code has been received from the phone network.
Indicates the SMS Lite tried to send an SMS but received an error code back from the phone network. Likely causes are having no credit on the SIM card or the cell tower being busy (no network availability) or invalid phone number for the SMS message recipient.

Status Indications

The SMS Lite status LED indicates these status information and events:

Heartbeat – 1 short flash every two seconds – OK – SMS Lite is connected to the cellular network.

Power Up – 5 slow flashes – displayed when the SMS Lite powers up.

Transmit OK – 5 short flashes – shows the SMS Lite successfully sent an SMS.

Transmit Fault – 3 long flashes – shows the SMS Lite tried to send but there was a problem.

This provides technical assistance for troubleshooting issues with the QTech SMS Lite.

Step 1 – Remove the top cover of the unit
Power down the device. The top cover is held in place using dimpled locators. The cover is “sprung” open by gently prising the lid corners up. A flat bladed screwdriver can be used to assist but avoid touching the electronics or scratching the device metalwork.


Step 2 – Insert a valid SIM card
Ensure the SIM has a valid SCA number, phone number and is known to be working (test in a phone beforehand if necessary). Insert the SIM card into the SIM socket, noting the correct orientation is observed. Bear in mind that not all SIMs can be used in all localities.


Step 3 – Power up the device to check operation
Connect the power adaptor to the unit and turn on the power. Do not touch the electronics. The device will indicate a burst of Status LED flashes on boot up then settle into a heartbeat flash (very short) every few seconds. During boot up the device may indicate an error code. If so, please note it down. As an added indication that it is working the modem LED on the modem daughterboard will slowly flash, on for 1sec off for 1sec, indicating that the device has registered on a network.


Step 4 – Send a test message
Send a test message to the device from a phone by creating a new text message to the device’s phone number: Test No PIN number is required for the test message.


Step 5 – Verify operation
If the device is operating OK the Status LED will indicate 1 short flash every two seconds. This is called the “Heartbeat” indication. When it receives the test message the Status LED will display a test pattern on the LED for a few seconds consisting of alternating short and long flashes (i.e., short flash-longer flash-gap-short flash-longer flash-gap).

You will see this pattern as many as 5 times. If the SIM is working properly the device will send a response text message “SMS Lite comms test succeeded” to the phone. When it sends this message there will also be a short burst of LED flashes to indicate that it is transmitting. If the device fails to do either or both of these, then there is a fault. If an error code is flashing, see the previous Status LED section to diagnose the fault, or contact QTech for assistance after working through the troubleshooting section below.


Step 6 – End of test
Power down and carefully replace the top lid. Then power up again.

Error Code 9 means that a non-specific or internal error has occurred and the device cannot accurately determine the cause. Common reasons for this code are: An invalid phone number has been programmed into the device, for example there are too many digits in it, or too few or it has the wrong prefix. In Australia all mobile numbers must start with 04 or +614. In New Zealand mobile numbers start with 02 or +642. Use the phones command to inspect the phone list for incorrect numbers. The SIM has no credit on the account, if you are using a prepay account the balance should be checked using the app provided by the Mobile Network operator and if necessary, topped up. The wrong kind of SIM is being used. If you were to put the SIM in a phone you could make a voice phone call with it. Some Data only SIMS will not work. Check with your SIM provider to confirm that it is a voice and data SIM.

These flash codes indicate a problem with trying to initialise the modem module. Removing the lid to the device will allow the user to view the LED indicator on top of the modem module itself. These problems usually require the unit to be returned for service but there are some checks that can be done beforehand If the indicator is on or flashing then this usually (not always) indicates that the modem module is functioning. If it is flashing then the modem has actually registered on a cell tower so the fault probably lies in the interface between the daughterboard and the motherboard or with the SIM. Error Flash code 2 can be a problem with: The power to the module had failed you would not see the indicator on the modem module in that case. If there is also no indication on the status LED then it is likely a power problem. If the indicator on the module does work the voltage may be just low in which case it will need servicing. Other issues may be a hardware fault such as a dry solder joint. If the SIM is faulty or not configured correctly by the Mobile Network Operator then it may prevent communications to the modem module so it might look like a module problem when in fact it is a SIM problem. Trying using the SIM in a phone to send a SMS message, if that does not work then it is the SIM at fault not the device. Visually inspect the modem module to see that it is correctly plugged into the socket on the motherboard Error Flash code 3 (and sometimes code 2) commonly occurs when: The contacts on the SIM are dirty or the SIM is incorrectly inserted, clean the SIM with a solvent like isopropyl alcohol. Me sure the SIM is and any breakouts for the smaller SIM sizes are intact. The SIM is preventing digital communications between the modem and the main processor (daughterboard and motherboard). Try the SIM in a phone. There is a hard fault with the connections between the modem and the processor. Visually inspect the modem module to see that it is correctly plugged into the socket on the motherboard

This usually means the master phone number has been programmed with an invalid number. Try again and do not forget to use the correct PIN number and terminate the command with a full stop (dot). One may also see the network error code (3 long flashes) if the any of the programmed phone numbers are incorrect and the device is trying to message them.

Check that the new SIM works in a phone. Check you can make a phone call with the new SIM. If the device appears to be operating normally but inserting a SIM from a new provider has caused it to stop, then using the old SIM, send the INFO command to obtain the firmware version number and note the response. The firmware may require updating to support the new SIM. Contact QTech for assistance.

Check for a power failure or blown fuse. Check that the SIM account is in Credit. Remove the SIM and try it in a phone and clear or delete any SMS messages (especially network generated messages.

Error code 5 flashes indicates that the SMS Lite cannot register on the network. Make sure that the antenna is screwed on properly. If the device flashes error code 5 (or 6) then the device may not be operating on a supported network possibly because the SIM is not provisioned correctly for the supported networks: Australia – Optus, Telstra. New Zealand – Spark, 2Degrees, One NZ (Vodafone). If the SIM works correctly in a phone, then the issue may be that the SMS Lite is in a poor location, move it into an open space out of any cupboard or enclosure, away from metal, other electrical equipment, above the floor . Error Code 6 indicates that the device is not registering and is operating in a country that is not supported by the device. Open the lid of the device and look at the indicator on the daughterboard. If it is on solid the device is searching for a network, this could be a cellular coverage issue. If it is flashing slowly the device has registered on a network but the SIM subscription may not be valid (unknow subscriber number) put the SIM in a phone and check it. If the indicator is off (after being on solid for some time) then the device cannot register on the network and it may be a network coverage or antenna issue.

The command estimates whether cellular coverage is acceptable. If messages are not sent or received reliably this may be due to: Poor connectivity to the cell tower, possibly due to range or terrain. SMS Lite antenna is obscured or enclosed diminishing receive signal strength. Antenna and cables are insecure and have been damaged. The antenna being used is inadequate for the situation. Verify all cables are secured and not subject to fretting or wind events. Elevate the antenna and place it outside. In severe cases the device will not register on the mobile network and shows an error flash code. Consider using a higher gain antenna, contact QTech for advice.

Turn Quiet mode to OFF and you will be prompted to acknowledge alarms. Make sure the escalation time is set to a reasonable value (more than 1 min say).

If the error code is replaced by the heartbeat indication (short flash every few seconds) then the device is in its normally operating mode and is registered on the mobile network. The typical boot sequence when the device starts is as follows: The device will turn the status LED on then flash briefly with a number of flashes (potentially error code 7 indicating the device is busy while starting up). Or the status LED may be off for approximately 20s.The device then attempts to register on the mobile network and may display error code 5 whilst waiting to register, once registered and initialisation completed the device should settle into the heartbeat LED indication. If an error code is repeatedly displayed, then this is the code that should be reported to QTech. Carefully note the actions of the status LED as it powers up and count the number of flashes in an error code when it is displayed, report this code to QTech for further support. If the unit is stuck, flashing Error code 7, the SIM card may not compatible with the SMS Lite, or incorrectly provisioned, contact QTech for assistance. See also below for troubleshooting specific error codes.

If there are no phones explicitly programmed for an input (see configuration) then when the input changes state the notification is sent to all phones in the phone book in the order PH1 to PH8 (whichever have a phone number associated).

This can occur on inputs that need “switch debounce” to prevent them chattering causing several messages to be sent. Increase the input debounce time for the inputs using the debounce command. Note. It is recommended that the debounce be configured as part of the initial setup before assigning names to inputs and outputs.

The message is normally sent whenever the unit is repowered to PH1. If it is not received: Ensure that the master phone PH1 has been programmed by sending the Phones command from the master phone to the unit Ensure that the sim is correctly inserted and that the sim contacts are clean and clear. Check that there is sufficient account balance or credit in the SIM if a prepay SIM is being used. If necessary, check by putting the SIM in a phone and sending a phone-to-phone SMS message. Check that the SIM is registering on the network. Check that the correct power supply and voltages are present to power up the device. The heartbeat status indication should be flashing on the status LED. If not then check the fuse.

If the info command works but the phones command does not then the user’s phone has not been added to the device phone list. Refer to the section “additional configuration” to add the users phone number to the list. If the user’s phone is in the phone list but only some messages are processed then check that the heartbeat flash indication is normally being displayed and that the device has powered up correctly. The problem may also occur if there is a (temporary) network delay in delivering messages across the mobile network. Insert the device SIM in a phone and send SMS messages to/from it with another phone. All messages should be delivered in both directions in a timely manner. If not then it may be a network issue, try again later. If the problem persists then the SIM may not be correctly configured for the network, contact the mobile network operator for assistance. The SIM may be configured as “DATA ONLY” SIM and not configured for SMS messages. Check with the Mobile Network Operator and always use SIMS that are configured for SMS messages up to 160 characters in length with no constraints on delivery quality of service.

Check the rest of this troubleshooting guide to make sure it is not a SIM or coverage issue. Use the Phones command to check your phone is in the list, note which slot number it is (1 to 8). Use the Inputs command to check that you phone slot number (1 to 8) is registered to receive messages from the input. Check the escalation time using the status command to see how long you should expect to wait in the escalation order. If the escalation time is 60 minutes and you are last in a full list of 8 phones you could be waiting 8 hours before getting a message. Try setting the escalation time to a shorter time to check that alarms are going out before setting it to a long time if you normally want a long escalation time delay.

This could be due to a blown fuse or the device is in an error state. Repower the device and look for the power up indication (5 flashes) within about 30s. If the status LED is not flashing at all then remove the lid and look on the modem module daughterboard for an indicator on or flashing. If there are not indicators on at all on the module daughterboard check the fuse and check that the power supply does not exceed the rated input voltage for the device. If the module LED is on solid but not flashing but then turns off then the device cannot register the SIM on the mobile network (see below). If the device powers on OK and shows the power up indication but nothing else then try another SIM that is known to be working or try the SIM in a phone.

The mobile network has rejected a message being sent by the device. This is primarily due to an incorrect phone number programmed into the Phone List. The Message will only ever be sent to Ph1 (the Master Phone). Use the phones command to list the phones. Try changing numbers to international format (+<Country Code, e.g. +61 for Australia)Look for numbers that are too long or short (no more than 13 digits including the country code prefix)Verify the phone numbers by sending them an SMS message from your phone in case the number is disconnected or not recognised.

If the SMS Lite was set up by someone else and they are the Master Phone (Ph1) then ask them to check that you are in the phone list or have your phone number added. After that you can use the Phones command to list the phone numbers.

This means the device can neither receive nor transmit test messages. The SMS Lite must be running a recent version of the firmware to process the test message. If the device was purchased prior to June 2019 then try programming the master phone number then sending the info command. If that responds then the SMS Lite is receiving and sending SMS messages. Stand near the device and check that you have reasonable network coverage (a few bars) on a mobile phone. Check all connections to the antenna are firm and that the antenna is in an open area away from or not enclosed in metal objects. Avoid long antenna cables (over 5m) and ensure low-loss coaxial cable is being used. If you are unsure about cellular coverage or antenna performance in rural areas, try setting up the SMS Lite in a location with known good cell coverage and check operations.

This could mean there is a problem with the SIM operating on the network because it could receive the test message but not send a response. If the network error (transmit fault) code is displayed after the test pattern then the network could not process the response message usually for one of these reasons: There is no credit on the SIM or mobile account. The SIM is incorrectly provisioned (some data-only SIMs cannot send SMS messages)The SMS service number (SMSC) is incorrect. The mobile network is busy. The SIM can be checked in a phone by sending a message from the phone. This will usually also set up the SMSC number if it is not correctly programmed in the SIM. Make sure the message is sent via SMS and not a messaging app (which typically uses data and not SMS). If the network is busy, wait a while and try again. If the problem continues try sending a message from your phone where the SMS Lite is located. If this succeeds the network is not busy and this is not the problem. Look for other error codes being displayed on the SMS Lite status indicator. Then see below. Remove the lid on the SMS Lite and check that the LED indicator on the modem daughterboard is flashing on and off slowly. If it is not then the device has not registered on the mobile network.

If you still can not find the answer please try typing your question in the search bar below:

For other SMS Lite FAQ, including selecting power supplies and SIM cards, click the link below.

SMS Lite & SMS Controller - Click here for Help and FAQ

Previously both the SMS Lite and SMS Controller supported texting “BAL” to get your current pre pay SIM card balance in NZ.

However, the Telco’s now provide a more convenient app and online capability to check account balances for both pre pay and on contract accounts.

Please use the telco’s app to check SIM card balances.

We have now discontinued this feature in SMS Lite firmware v4.10.

Neither the SMS Lite nor SMS Controller account balance feature works in Australia.

Do not use spaces in the SMS Lite naming convention for the Site Name, Inputs or Outputs.

For example, “Back Gate” should read “BackGate” and “High Level” should read “HighLvl”.
Remember to keep the names less than 8 characters long.

Use only alphanumeric characters, avoid punctuation and special characters

Keep all names as short as practicable.

Do not use reserved keywords in names. ON, OFF, NAME, PHONE, SITE, DEBOUNCE, DEFAULTS, OK, BUSY, PULSE , STATUS, BAL, STATS,  INFO, INPUTS, OUTPUTS must all be avoided.

Always check the spelling in the message you sent.

Further details are in the user guide.

The SMS Lite has been used many times to remotely start generator at holiday homes etc by simply sending a text message.

SMS Lite - generator remote start

This application note details some useful advice and considerations.

Simply text “status” to the SMS Lite – the reply text will contain the battery voltage and the value of all the inputs and outputs.

Further details are in the user guide.

The “standard” larger size SIM is used in both the SMS Lite and SMS Controller. Don’t pop the smaller sizes out of the plastic holder they come in.

SIM card sizes

The SIM card must support sending text messages – do not attempt to use “data only” SIM cards. Please mention this to your chosen Telco when choosing the SIM card and plan.

QTech offer a range of suitable power supplies and plug packs for our solutions. Please watch this short video for guidance on which power supply to select.

Setting up the SMS Lite is straight forward, please watch this short video for a demonstration.

Please watch this short video to see how to configure the SMS Lite.

Yes they are. DATRAN Australia Pty Ltd was formed to actively supply, promote and implement the tried and proven telemetry products into Australia and the surrounding markets.

Please contact Ross Gregory on ross.gregory@datran.com.au