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
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
07/10/2026
Dalet, a leading technology and service provider for media-rich organizations, today announced the latest Long-Term Supported (LTS) release of Dalet Flex. Build...
06/09/2026
June 9 2026, 23:00 (PDT) Dolby and MagentaTV Bring Fans Closer to the FIFA Worl...
04/08/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
15/07/2026
The 2026 FIFA World Cup is a big deal for DAZN, which has distribution rights in three markets: Italy, Spain, and Japan. Each requires a different editorial app...
15/07/2026
As sports-media organizations manage rapidly growing content libraries and incre...
15/07/2026
HBS director of digital Johannes Franken talks SVG Europe through the operation built to serve FIFA World Cup 2026 rights holders remotely from Stratford, east ...
15/07/2026
IBC has unveiled the conference program for IBC2026, with this year's event ...
15/07/2026
Software-defined wideband RF platform supports 96-kHz monitoring, streamlined fr...
15/07/2026
New AI-powered module enables broadcasters and content owners to extract dialogu...
15/07/2026
Weeklong gathering at EBU headquarters will test new IPMX capabilities and expand certified product ecosystem...
15/07/2026
Force Tech has announced the appointment of Bryan Adams, CTS, as Vice President of Integration. Adams will oversee AV and broadcast integration project delivery...
15/07/2026
USA Sports has announced an exclusive English-language agreement with the Bundes...
15/07/2026
ITV Sport's FIFA World Cup 2026 coverage has been produced from one of the m...
15/07/2026
Program will provide professional camera kits, training, and technical support to participating local newsrooms...
15/07/2026
San Francisco church becomes first U.S. deployment of the 2 M/E production switcher...
15/07/2026
Former ESPN and NFL Network executive to advise startup league on media, distribution, technology, and fan engagement...
15/07/2026
The Houston-based RSN is the live-game home of the Astros and Rockets...
15/07/2026
Launched alongside new FreqSoft installer
Designed to bridge the gap between hardware and software, Freqport's FreqInOut FO1 unit provides a simple way ...
15/07/2026
Save up to 55% on software until 23 July 2026
Expressive E have just launched their Summer Offer sale, with discounts of up to 55% now applied across their ...
15/07/2026
Real-time stem-separation tool updated
zplane have recently released a new and improved version of their real-time stem-separation plug-in which they say ma...
15/07/2026
A new benchmark in bass enhancement
Described as a new benchmark in bass enhancement , Baby Audio's latest release has been designed to augment the lo...
15/07/2026
DMC Production's AR 1 and AR 2 units reverse the conventional OB workflow, keeping all production-critical processing at the venue while operators work remo...
15/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
15/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
15/07/2026
GigaCloud, a leading Ukrainian cloud service provider, and Cubbit, the first geo-distributed cloud storage enabler, today announced a new Business Alliance Part...
15/07/2026
SMPTE, the global society for media professionals, technologists, and engineers, has announced the launch of the SMPTE 110th Anniversary Campaign, a fundraising...
15/07/2026
Studio Technologies, a leading manufacturer of high-quality audio, video, and fiber-optic solutions, unveils the new StudioComm Model 762 Stereo Level Control, ...
15/07/2026
COW Jobs: Producer, Virtual Events - Hybrid, Full Time, Salaried
Brie Clayton July 15, 2026
0 Comments
Producer, Virtual Events (Hybrid | Full-time | ...
15/07/2026
Brazilian media organization builds nationwide CDN with Broadpeak's high-performance software for low-latency streaming and new content distribution service...
15/07/2026
DHD announces a new utility designed to increase the efficiency of its audio mixing systems during initial installation and subsequent configuration.
Anyone w...
15/07/2026
BCNEXXT Brings Next-Generation Vipe to IBC2026, Breaking the 1:1 Channel-to-Server Ratio New innovations liberate broadcasters from legacy playout infrastructur...
15/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
15/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
15/07/2026
Wednesday 15 July 2026
Screeners and press pack now available: Gomorrah: The Or...
15/07/2026
Trinity's Treasures features Ruth Negga, Eleanor McEvoy, and David Norris, a...
15/07/2026
Join geographer Dr Susan Hegarty, Engineer Tim Joyce and Architect Orla Murphy a...
15/07/2026
Home to leading manufacturers, robotics pioneers, infrastructure builders and gaming, of course, Japan is one of the world's centers of AI - building across...
14/07/2026
South end zone videoboard, cloud-based control system will be ready for 2026 football season...
14/07/2026
Redesigned website, enhanced mobile app unify content, ticketing, and personalized fan engagement...
14/07/2026
Agreement spans sponsorship sales, digital monetization, radio production, and new practice facility naming rights...
14/07/2026
Independent league adds 14 regional sports network affiliates, growing distribut...
14/07/2026
New strategy aims to unify competitions, content, fan engagement, and commercial...
14/07/2026
ESPN and Disney+ become exclusive home of PFL events in key international MMA market...
14/07/2026
Gill will oversee engineering, technology, and sports operations across the company's 64 local television stations...
14/07/2026
Submitted by North American Broadcasters Association (NABA)
As broadcasters con...
14/07/2026
Modernized mobile unit combines HOME Apps, mc 56 console, and IP infrastructure ...
14/07/2026
Every match of the 32-team tournament will air across ION and Scripps Sports platforms in English and Spanish...
14/07/2026
FloHockey to stream every game of the annual international tournament under four...
Applicable Products Part number Description 
