
Applicable Products Part number Description
ZETA-GEP-LTE4 (EU) Low Power LTE Cat 4 European Modem with GPIO and GNSS
ZETA-G-GPRS Entry Level GPRS Modem with GNSS (GL)
ZETA-N2-GPRS Entry Level GPRS Modem (GL)
ZETA-NEP-LTE4 (EU) Low Power LTE Cat 4 European Modem with GPIO
ZETA-NEP-LTEM (GL) Low Power Global LTE Cat M Modem with GPIO
ZETA-NLP-LTE1 (EU) Ultra Low Power European LTE Cat 1 Modem
ZETA-NLP-LTEM (GL) Ultra Low Power Global LTE Cat M Modem
ZETA-N-LTE (EU) High Performance LTE Cat 4 Modem with GPIO
ZETA-NSP-LTE1 (EU) Low Power European LTE Cat 1 Modem
Objective Once a Siretta ZETA modem is powered on, a combination of its 3 LEDs light up, showing different stages of modem connection to a network (default state).
Also, assuming the network connection is achieved, the modem can send a receive AT commands.
If any of the above fails to materialise, a troubleshooting procedure will help to investigate and solve basic issues.
Solution This application note covers the following:
No LED indication
Modem keeps rebooting
Failure to connect to a modem serial port
No response from the modem when using AT commands
No Carrier when dialling Voice/ data calls
Demonstration of Solution LEDs Not Lit
Check the modem has been connected to the correct power supply
Check the power connector is inserted correctly
Check the power has been switched on at the mains
Check the LED functionality has been set with either AT#SLED or AT#GPIO AT commands
Modem Reboot If your Siretta modem keeps rebooting, please check the following procedures:
Check the SIM card has been inserted correctly
Check the power supply is correctly specified or you are using an approved Siretta PSU.
No Serial Connection If your Siretta modem has no serial connection, please check the following procedures:
Check the serial cable has been inserted correctly
Check the serial cable has the correct pin alignment (see below)
Check the modem emulator program has the proper settings (Factory settings = 115200, 8, n, 1)
Check there isn't another program interfering with the communication program
Check there isn't a conflict with communication port access
RS232 Serial Port Interface This connector provides serial RS232 communication between ZETA-xxP modem and the connected equipment. The modem can be configured via the RS232 connection using AT commands as specified in the AT command manual.
Table 15. Pins Usage
Pin Name Usage Status Direction
1 DCD Output from UART that indicates the carries is present Connected OUT
2 RXD Output transmit line of UART Connected OUT
3 TXD Input receive line of UART Connected IN
4 DTR Input to UART and controls DTE ready condition
Connected IN
5 GND Ground
Connected IN
6 DSR Output from UART that indicates the module is ready
Connected OUT
7 RTS Request to Send - Input line of UART that controls hardware flow control
Connected IN
8 CTS Clear to Send - Output line of UART that controls hardware flow control
Connected OUT
9 RI Ring Indicator- Output line of UART that indicates the incoming call condition
Connected OUT
Supported baudrates
>> 2400 >> 38400
>> 4800 >>57600
>> 9600 >>115200
>> 19200 >230400
No Carrier Message If your Siretta modem returns a No Carrier' message upon an attempted call (voice or data), please consider the following possible causes:
If the modem returns Then ask? Action
No Carrier' Is the received signal strong enough? Use AT+CSQ' to check RSSI.
Check signal strength indication. *
Is the antenna connected correctly? Ensure antenna is firmly screwed into place.
No Carrier'
(When trying to issue voice communication) Is the semicolon ( ; ) entered immediately after the phone number in the AT command? Ensure that the semicolon ( ; ) is entered after the phone number in the AT command. (e.g. ATD123456:)
No Carrier'
(When trying to issue data communication) Is the SIM card configured for data/fax call? Configure the SIM card for data/fax calls. (Ask your network provider if necessary)
Is the selected bearer type supported by the called partly? Ensure the selected bearer type is supported by the call party.
Is the selected bearer type support by the network? Ensure the selected bearer type is supported by the network.
If no success, try bearer select type by AT COMMAND: AT+CBST=0,0,3'
Value of RSSI Interpretation
0 to 12 Insufficient or weak
13 to 19 Average
20-31 Good
99 No Signal
Additional Reading Description Author
ZETA Hardware user's manual Siretta
AT command manual Telit
Quick Start Guide Siretta
Post Views: 32
Most recent headlines
04/09/2025
Monumental Sports & Entertainment (MSE), in collaboration with Dalet, has been a...
28/04/2025
Podcasts have become a cornerstone of the Spotify experience, evolving from a ni...
28/04/2025
Each April, runners and walkers of all stripes gather together in Lower Manhattan for the 9/11 Memorial & Museum 5K. This race remembers those killed on Septemb...
28/04/2025
MELBOURNE, Fla., April 28, 2025 - L3Harris Technologies (NYSE: LHX) Chief Financial Officer and Aerojet Rocketdyne President Ken Bedingfield will present at Bar...
28/04/2025
HACKENSACK, NJ LiveU, a global provider of live IP-video contribution, production and distribution solutions, has signed a definitive agreement to acquire Actus...
28/04/2025
LiveU, the global leader in live IP-video contribution, production and distribution solutions, has signed a definitive agreement to acquire Actus Digital's ...
28/04/2025
Ikegami Electronics (Europe) will promote the latest additions to its range of broadcast-quality television production equipment at Broadcast Innovation Day (BI...
28/04/2025
Intinor is once again set to collaborate with its UK partner Zest Technologies at MPTS 2025 (Olympia, 14-15 May 2025). Following the recent launch of key update...
28/04/2025
CJP Broadcast, the UK-based systems integrator specialising in virtual production and broadcast studio design, installation, commissioning and support, will ret...
28/04/2025
The media landscape in the Middle East continues to see a rise in OTT platforms, regional content creation, and expanding viewer expectations, which means the d...
28/04/2025
Clear-Com has announced the appointment of StreamPort Media as its authorized distributor in the Middle East. This partnership will expand access to Clear-Com&...
28/04/2025
nxtedition will showcase its unified production platform at CABSAT 2025, featuring advanced AI automation, open-source integrations and a seamless approach to l...
28/04/2025
nxtedition will demonstrate its story-first production platform at MPTS 2025, highlighting integrated AI Agents, open-source language models, and frictionless c...
28/04/2025
Keepit has teamed with Ingram Micro, a leading business-to-business platform company for the global technology ecosystem, to expand access to Keepit's vendo...
28/04/2025
Ross Video, a global leader in video production technology, is participating in CABSAT 2025, taking place at the Dubai World Trade Center.
CABSAT is the leadi...
28/04/2025
Disguise, the leading platform and solutions provider driving the next generation of visual experiences, has appointed Jake Stone as its Senior Vice President o...
28/04/2025
Lightware, a global leader in connectivity and signal management solutions, is set to return to InfoComm 2025 with a dynamic showcase of industry-first innovati...
28/04/2025
arkona technologies GmbH, provider of cutting-edge IP core infrastructure solutions has announced that its EASY-IP platform is the recipient of Future's Bes...
28/04/2025
TMT Insights wrapped up an award-winning NAB 2025 with two of its high-profile customer engagements recognized with Project of the Year Awards: Content Acquisit...
28/04/2025
Fix Format Issues & Enhance Videos 80% Faster with VideoProc AI - Major Update
Brie Clayton April 25, 2025
0 Comments
VideoProc Converter AI just got ...
28/04/2025
New in Premiere Pro and After Effects at NAB 2025 - Larry Jordan with Kylee Pe a...
28/04/2025
The Text Selector Expression is arguably the most elusive Adobe After Effects Fe...
28/04/2025
Master your music for free with a new desktop app from Brainworx
Brie Clayton April 27, 2025
0 Comments
bx_mastering studio promises free streaming-re...
28/04/2025
LiveU Inks Deal to Acquire Actus Digital, Boost Video Monitoring and Analytics C...
28/04/2025
Small Van, Big Story: Changing the Game in Sports Broadcasting with Obvious C By SVG Staff
Monday, April 28, 2025 - 10:51 am
Print This Story | Subscribe ...
28/04/2025
SVG Sit-Down: ESPN's Chris Calcinari on New Flagship Mobile Unit, Cloud and ...
28/04/2025
A Swiss Soccer Summer: Previewing UEFA Women's Euros 2025 with BBC Sport and...
28/04/2025
Monday 28 April 2025
New research from Sky Sports, released today, shows that w...
28/04/2025
Monday 28 April 2025
To view this content, please enable our use of cookies. To...
28/04/2025
After 20 Legendary Seasons Sky is Hanging Up The Boots of its BAFTA-winning Sports Show. Production of farewell series tees off this summerMonday 28 April 2025
...
28/04/2025
Back to All News
Netflix Celebrates the Creative Tapestry of APAC Films at Tokyo Showcase
Entertainment
28 April 2025
GlobalJapanSouth KoreaIndiaThailandInd...
28/04/2025
Back to All News
Get Ready for Netflix Tudum 2025: The Live Event! Watch the Tr...
28/04/2025
As enterprises increasingly adopt AI, securing AI factories - where complex, agentic workflows are executed - has never been more critical.
NVIDIA is bringing ...
28/04/2025
Agentic AI is redefining the cybersecurity landscape - introducing new opportunities that demand rethinking how to secure AI while offering the keys to addressi...
28/04/2025
Oracle has stood up and optimized its first wave of liquid-cooled NVIDIA GB200 N...
27/04/2025
It's with deep regret that we share the passing of our dear friend Bruce Logan, ASC.
Bruce was not just a collaborator-he was family. He worked with us at ...
27/04/2025
Back to All News
KAULITZ & KAULITZ - Launch date and first look for season 2
Entertainment
27 April 2025
GlobalGermany
Link copied to clipboard
KAULITZ & ...
27/04/2025
Back to All News
Senna Wins Best Series Creator Category At The 2025 PLATINO Awards
Entertainment
27 April 2025
GlobalBrazil
Link copied to clipboard
This...
27/04/2025
Back to All News
Masterclass With Creative Team Behind Adolescence Takes Filmma...
26/04/2025
NEW YORK Samsung Ads has debuted a new interactive advertising format, Creative Canvas, that helps automate and deliver interactive ads....
26/04/2025
WEST PALM BEACH, Fla. Sinclair has appointed Vincent J. Sollecito vice president and general manager of WPEC, serving the West Palm Beach, Florida market....
26/04/2025
NEW YORK and DENVER AD-ID and Comcast Technology Solutions (CTS) have announced that they are working together to promote the adoption of industry standards in ...
26/04/2025
Cobalt Scores a Trifecta of Awards at NAB 2025
Brie Clayton April 25, 2025
0 Comments
Company adds another Best of Show and two Product of the Year tr...
26/04/2025
FilmLight Colour Awards welcomes 2025 entries
Brie Clayton April 25, 2025
0 Comments
Entries open from 1 May 31 July to colourists on any grading pl...
26/04/2025
Blackmagic's Latest Products - Larry Jordan Guest Spots with Dan May at NAB ...
25/04/2025
Emily Watson, Isaiah Saxon, Helena Zengel, and Finn Wolfhard at The Legend of Ochi premiere (photo by Soul Brother/Shutterstock for Sundance Film Festival)...
25/04/2025
Using its CORVUS portfolio, L3Harris created a highly adaptable battle network t...
25/04/2025
Agile Content joins forces with Tiscali to introduce a new platform in Italy, of...
25/04/2025
The company positions Agile TV as the commercial brand focused on delivering TVaaS solutions for operators and media.
The chosen tagline TVaaS your way enca...
25/04/2025
A Fully Managed Solution That Maximizes Revenue for North American Operators Whi...