Overview
This guide explains SMS messaging functions available on Siretta industrial modems. It covers SMS configuration, text mode messaging, PDU mode operation, message storage, sending and receiving SMS messages and troubleshooting SMS communication.
| Part Number | Description |
|---|---|
| ZETA-GEP-LTE4 (EU) | Low Power LTE Cat 4 European Modem with GPIO and GNSS |
| ZETA-NEP-LTE4 (EU) | Low Power LTE Cat 4 European Modem with GPIO |
| ZETA-N-LTE (EU) | High Performance LTE Cat 4 Modem with GPIO |
| ZETA-NSP-LTE1 (EU) | Low Power LTE Cat 1 Modem |
| ZETA-NLP-LTE1 (EU) | Ultra Low Power LTE Cat 1 Modem |
| ZETA-G-GPRS | GSM/GPRS Modem with GNSS |
| ZETA-N2-GPRS | GSM/GPRS Modem |
This guide demonstrates how to:
Expected Result
At the end of this guide the modem should be capable of sending and receiving SMS messages successfully.
SMS messaging allows short text messages to be transmitted over the cellular network.
Siretta industrial modems support:
Before sending SMS messages the modem must be configured for either:
Text mode is simpler and easier to use for testing and integration.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGF=1 |
| Command | Description |
|---|---|
AT+CMGF=1 |
Enables SMS text mode |
Expected Result
The modem should enable SMS text mode successfully.
PDU mode provides low-level control of SMS message encoding.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGF=0 |
| Command | Description |
|---|---|
AT+CMGF=0 |
Enables SMS PDU mode |
Important Note
PDU mode is commonly used in embedded systems and advanced SMS applications.
SMS messages can be transmitted directly using AT commands.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGS="+447700900000"
> Hello from Siretta modem +CMGS: 25 |
| Command | Description |
|---|---|
AT+CMGS |
Sends SMS message |
CTRL+Z |
Terminates and transmits message |
Important Note
The message is only transmitted after pressingCTRL+Z.
The modem can receive and store incoming SMS messages.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CNMI=2,1,0,0,0 |
| Parameter | Description |
|---|---|
2 |
Buffer unsolicited indications |
1 |
Display new SMS notifications |
When a new SMS message arrives, the modem can automatically generate an unsolicited notification.
| COM3 - SMS Notification |
¶ File Edit Setup Control Window Help |
|
+CMTI: "SM",3 |
| Field | Description |
|---|---|
SM |
SIM card storage |
3 |
Message index location |
Stored SMS messages can be read individually.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGR=3 +CMGR: "REC UNREAD","+447700900000","","25/05/26,12:15:10+00" OK |
| Command | Description |
|---|---|
AT+CMGR=3 |
Reads SMS at index 3 |
All stored messages can be displayed using the message list command.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGL="ALL" +CMGL: 1,"REC READ","+447700900000","","25/05/26,11:15:00+00" +CMGL: 2,"REC READ","+447700900001","","25/05/26,11:45:00+00" OK |
| Command | Description |
|---|---|
AT+CMGL="ALL" |
Lists all stored SMS messages |
Messages can be deleted individually or in groups.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CMGD=3 |
| Command | Description |
|---|---|
AT+CMGD=3 |
Deletes SMS message index 3 |
SMS messages can be stored in either modem memory or SIM card memory.
| COM3 - Tera Term VT |
¶ File Edit Setup Control Window Help |
|
AT+CPMS? +CPMS: "SM",3,50,"SM",3,50,"SM",3,50 OK |
| Field | Description |
|---|---|
SM |
SIM card storage |
3 |
Stored messages |
50 |
Maximum capacity |
| Problem | Possible Cause | Solution |
|---|---|---|
| SMS not sending | Network registration issue | Verify network registration |
| No incoming messages | Notification disabled | Configure CNMI settings |
| Memory full | Storage exhausted | Delete old messages |
| Message rejected | Invalid destination number | Verify recipient number |
| No SMS service | SIM restriction | Check SIM provisioning |
| Step | Action |
|---|---|
| 1 | Configure SMS mode |
| 2 | Enable SMS notifications |
| 3 | Send SMS messages |
| 4 | Receive SMS messages |
| 5 | Read stored messages |
| 6 | Manage SMS storage |
| 7 | Troubleshoot SMS operation |
Support
For further assistance, please contact the Siretta support team.