Sony Pixel Power calrec Sony

Modem Troubleshooting

27/03/2025

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
LINK: https://www.siretta.com/2025/03/modem-troubleshooting/...
See more stories from sequoia

Most recent headlines

05/01/2027

Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be demoed at CES 2026

Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...

04/08/2026

Dalet Announces Commercial Availability of Dalia, Bringing Media-Aware Agentic AI to Enterprise Productions

Dalet, a leading technology and service provider for media-rich organizations, t...

04/07/2026

Detective Conan: Fallen Angel of the Highway Opens in Dolby Cinemas Across Japan, Presented in Dolby Atmos and Dolby ...

April 7 2026, 19:00 (PDT) Detective Conan: Fallen Angel of the Highway Opens in...

01/06/2026

Dolby Sets the New Standard for Premium Entertainment at CES 2026

January 6 2026, 05:30 (PST) Dolby Sets the New Standard for Premium Entertainment at CES 2026 Throughout the week, Dolby brings to life the latest innovatio...

02/05/2026

Dalet Flex LTS Delivers Smarter Search, Faster Editing, and an AI-Ready Foundation for Modern Media

Dalet, a leading technology and service provider for media-rich organizations, t...

01/05/2026

NBCUniversal's Peacock to Be First Streamer to Integrate Dolby's Full Suite of Premium Picture and Sound Innovations

January 5 2026, 18:30 (PST) NBCUniversal's Peacock to Be First Streamer to ...

15/04/2026

BBC World Service TV Selects Open Broadcast Systems IP Decoders for Global Distribution

Open Broadcast Systems has announced that BBC World Service has selected its IP ...

15/04/2026

NAB 2026: LiveU Expands Collaboration with Sony to Include File-Based Workflow Integration

LiveU has announced an expansion of its collaboration with Sony Corporation, add...

15/04/2026

NAB 2026: Ateme and NVIDIA Announce Immersive Video Workflow for Apple Vision Pro

Ateme has announced a collaboration with NVIDIA to support live Apple Immersive ...

15/04/2026

Professional Fighters League Renews Multi-Year Partnership with DAZN DACH

The Professional Fighters League (PFL) has announced a multi-year partnership renewal with DAZN DACH, covering Germany, Switzerland, Austria, Liechtenstein, and...

15/04/2026

NAB 2026: Canon Sets New Benchmark with CINE-SERVO 40-1200m Lens; New Remote Camera Controller Supports Up to 200 Cameras

Canon U.S.A. (NAB Booth C3825) today took the lid off of the CINE-SERVO 40-1200m...

15/04/2026

NAB 2026: Panasonic and NEP Group to Demonstrate KAIROS and NEP Platform Integration

Panasonic Video and Audio Systems North America and NEP Group will demonstrate a...

15/04/2026

Exclusive Wasabi Report: AI Spending Is Surging, But ROI Tells a Different Story

For the fourth year running, independent analysts found businesses across all industries and verticals pay roughly the same amount in fees as they spend on stor...

15/04/2026

NBC Sports to Broadcast The Soccer Tournament Live on NBC, Peacock, and NBCSN, May 30-June 1

The Soccer Tournament (TST) has announced a media rights deal with NBC Sports to...

15/04/2026

NAB 2026: JB&A Announces Exhibitors for Pre-NAB 2026 Technology Event

JB&A will host the Pre-NAB 2026 Technology Event on April 17-18 at Flamingo Las Vegas, ahead of NAB Show. The event features hands-on demonstrations and technic...

15/04/2026

NAB 2026: Sennheiser Group to Exhibit with Spectera and AMBEO Updates

The Sennheiser Group will exhibit at NAB Show 2026 (Booth 4931, Central Hall), with demonstrations from Sennheiser, Neumann, and Merging across three areas: Rel...

15/04/2026

NAB 2026: NAB Show 2026 to Feature Expanded AI, Sports, and Creator Economy Programming

NAB Show 2026 will take place April 18-22 at the Las Vegas Convention Center, wi...

15/04/2026

NAB 2026: AI-Media Launches LEXI Text Encoder and LEXI Voice Encoder

AI-Media has announced the LEXI Text Encoder and LEXI Voice Encoder at NAB Show 2026, the company's first new encoder hardware release in more than a decade...

15/04/2026

NAB 2026: Cartoni Debuts New Camera Support Products

Italian camera support manufacturer Cartoni will introduce several new products at NAB Show 2026 (Booth C6540, Central Hall), including the Master 30 OB fluid h...

15/04/2026

NAB 2026: Lawo and swXtch.io Sign MOU to Explore groundSwXtch Integration

Lawo and swXtch.io have announced a memorandum of understanding at NAB Show 2026, under which Lawo will explore incorporating swXtch.io's groundSwXtch softw...

15/04/2026

NAB 2026: CacheFly to Demonstrate New CDN Features

CacheFly will exhibit at NAB Show 2026 (Booth W3129, April 19-22, Las Vegas Convention Center), showcasing three new additions to its content delivery platform:...

15/04/2026

NAB 2026: Synamedia Launches GO Shorts for Mobile-First Short-Form Video

Synamedia has announced GO Shorts, a new module within its Synamedia Go OTT platform that uses AI to convert an operator's existing content library into a s...

15/04/2026

NAB 2026 Preview, Central Hall: Everything You Need To Know Heading Into the Show

The NAB Show kicks off on Saturday, and the SVG and SVG Europe editorial teams a...

15/04/2026

AJA Video Systems to Acquire Video Encoding Software Company Comprimato

AJA Video Systems has announced an agreement to acquire Comprimato, a live video encoding and processing software company. The deal will unite the two companies...

15/04/2026

NBA Playoffs 2026: Prime Vision, Prime Insights Offer New Data-Driven Experiences for NBA Fans

Prime Video Sports' NBA Playoffs coverage, which includes the entire SoFi NB...

15/04/2026

Top Live-Sound-System Manufacturers Team Up To Better Manage Stadium Noise

Just announced, the SDE standard provides a unified method and file format to ensure consistent and reliably comparable noise predictions Sports and entertainm...

15/04/2026

Spotify Podcast Awards Return to Celebrate Latin America's Most Influential Voices

From immersive storytelling to laugh-out-loud comedies, podcasts are booming in ...

15/04/2026

Spotify Expands Audiobook Features, and Printed Book Sales Go Live in the US and UK

Books have always moved with us, whether tucked in our bags or humming in our he...

15/04/2026

Spotify and NIVA Partner to Support Independent Venues Across the US

For many artists, independent venues are where music careers begin and fan communities take shape. Independent venue operators work hard every day to keep local...

15/04/2026

Spotify Editors Reveal Their Picks for Best Book of the Century (So Far)

From gripping thrillers to poignant memoirs, the 21st century has had no shortage of unforgettable books. To celebrate the standout storytelling of our modern e...

15/04/2026

SonicWorld introduce Telsie T

Vintage broadcast experts release second plug-in Telsie T is the second plug-in to be released by SonicWorld, a German audio company who specialise in servi...

15/04/2026

UAD Explore Free from Universal Audio

Includes eight free UAD plug-ins Universal Audio's latest bundle brings together a selection of their renowned plug-ins and virtual instruments, and is ...

15/04/2026

Maximum uptime for broadcasters: Rohde & Schwarz launches R&SBroadcastShield at NAB 2026

Maximum uptime for broadcasters: Rohde & Schwarz launches R&S BroadcastShield at...

15/04/2026

WIDOW: The Mission Software Defining Rotary Strike

Image courtesy of MD Helicopters...

15/04/2026

L3Harris Announces Billion Dollar Expansion to Boost Solid Rocket Motor Production in Orange County, Virginia

Virginia Gov. Abigail Spanberger, L3Harris VP Mark Farley, and state and local l...

15/04/2026

Advancing America's Space Defense: L3Harris Completes Critical Milestone on Way to Delivering GBOSS Capability to the Warfighter

U.S. Space Forces Ground-Based Optical Sensor System upgrade at the Maui Space S...

15/04/2026

Winter Olympics, Super Bowl Power NBCU-Versant to Gold Medal Performance in Nielsen's February Gauge Reports

NBCU-Versant notches 13.1% of TV viewing in February, its best since August 2024...

15/04/2026

Nielsen CMI shows New Zealand's over-65s are a growing, cashed-up and still-working audience brands can't ignore

New data reveals older Kiwis are financially resilient, loyal to local products,...

15/04/2026

aconnic launches ACCEED 4430 10 Gigabit system for high volume enterprise and business service aggregation

aconnic AG (ISIN: DE000A0LBKW6), Munich, announces the market launch of the ACCE...

15/04/2026

Autocue to Mark 2026 NAB Show Debut of its New PTZ Prompter

Share Copy link Facebook X Linkedin Bluesky Email...

15/04/2026

Locality Deploys Nielsen's Media Data Engine

Share Copy link Facebook X Linkedin Bluesky Email...

15/04/2026

Viant Announces Agreement to Acquire TVision

Share Copy link Facebook X Linkedin Bluesky Email...

15/04/2026

Evergent introduces Agentic Revenue Orchestration Platfor...

Evergent introduces its Agentic Revenue Orchestration Platform, transforming how subscription businesses across direct-to-consumer streaming, pay-TV, telecommun...

15/04/2026

CentralCast Delivers Breakthrough Efficiencies to Public...

Harmonic's XOS Media Processor Delivers Exceptional Video Quality to More than Half of U.S. Public Media Viewership Harmonic (NASDAQ: HLIT) today announce...

15/04/2026

DPA N Series Wireless System Unlocks Duplex Gap and Guard...

LONGMONT, COLORADO, APRIL 15, 2026 DPA Microphones N Series Digital Wireless System users in North America can now take full advantage of the system's exc...

15/04/2026

Cobalt Iron Launches Compass Tape Gateway Modernizing IBM...

Cobalt Iron, a leading provider of SaaS-based enterprise data protection, today announced the launch of Compass Tape Gateway (CTG), a transformative enhancemen...

15/04/2026

Disguise to Showcase Cutting-Edge Experience Tech for Sports, Broadcast and More at NAB 2026

Disguise to Showcase Cutting-Edge Experience Tech for Sports, Broadcast and More...

15/04/2026

Arooj Aftab Makes the Music She Wants to Hear

Arooj Aftab Makes the Music She Wants to Hear The singular artist explores the juxtaposition of grief and joy, dark and light, in her distinctive sound. Apri...

15/04/2026

Panasonic, NEP Partner on IP-Based Live Production

Share Copy link Facebook X Linkedin Bluesky Email...

15/04/2026

Encompass Digital Media Powers Global Cloud Transformatio...

Interra Systems, a provider of end-to-end quality assurance solutions for the digital media industry, is proud to announce its central role in the digital trans...