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 To connect embedded systems together using the internet requires the use of data sockets to send information from one location to another. This process has been around for a long time and there are methods available to communicate with servers and devices using sockets to establish a bi-directional communication link between two endpoints.
In general, there is a listening device and a dialling device. Servers are generally setup as listening devices and remote modems as dialling devices, but this is not always the case and there are many examples which differ from this generalisation.
There are certain requirements with both the listening devices and dialling devices which must be taken into consideration when setting up a communication link between two endpoints. This application note will discuss these points in more detail.
Solution Listening Device Requirements The listening device must be accessible on the network and be able to accept incoming data socket requests from remote devices. This usually means having a firewall with a few specific open ports to allow incoming requests to be accepted through the accessible ports. Devices on the internet which have open ports are immediately susceptible to attack from hackers, spammers, viruses and bots which exploit specific vulnerabilities in the listening device's operating system. As a result, many security measures have been developed to prevent unauthorised access, but care must be taken to ensure that these measures are effectively managed.
For a device listening on the internet, it would usually have a fixed IP address which does not change over time. This IP address can then be used by any remote device to communicate with the listening device in a comparable way to a phone number is used on a telephone.
This fixed IP address would be publicly available and any device legitimate or otherwise would be able to communicate with it. On a HTTP webserver, the server would have a fixed IP address and would be listening for incoming data traffic on port 80. Mapped to this IP address would be a domain name such as www.example.com'. When the user types in www.example.com' to their web browser, the web browser looks up the IP address using DNS and it returns the IP address of the server. The web browser then contacts the server's IP address directly on port 80 and the https webserver responds with the web page.
The exact same process can be applied to data socket connections using mobile devices.
The mobile device uses a fixed IP address SIM card.
The mobile device is setup to listen on a specific port i.e. 1024.
The mobile device opens its firewall to specific devices.
The mobile device waits for an incoming data socket connection.
The dialling device attempts to open a socket on the IP address of the fixed IP address SIM card on the listening port i.e. 1024
Dialling Device Requirements The dialling device can use any standard SIM card and does not require a specific setup or fixed IP address SIM card. As the dialling device is dialling out to the server it is not listening for incoming data connections and therefore does not need to be as concerned about security as the listening device.
Demonstration of Solution Resources:
PC with an installed Terminal Emulator' program: A Windows 10 laptop installed with Tera Term was used for the purpose of this guide.
Siretta Part Number: 61057 -ZETA-GEP-LTE4 (EU) Starter Kit (any ZETA starter Kit is suitable for this application)
Insert SIM card to the modem
Power on the modem
Connect the supplied serial port cable to the PC
Connect the antenna
As described in the Starter Kit Quick Start Guide
Open Hyperterminal on the PC (or your preferred terminal emulator: PuTTY, TeraTerm).
Select new connection. Name the new connection for reference in the future.
Name your port.
Choose the correct COM port. From the drop-down list, select the correct COM port your modem is connected to.
Configure the port with the following settings (These settings are standard for all of the ZETA Siretta modems):
Bits per second: 115200
Data bits: 8
Parity: None
Stop bits: 1
Flow control: Hardware
Note: The above procedure is set out in Initial Modem Set Up application note
GPRS Connection COM3 - Tera Term VT
File Edit Setup Control Window Help
//Set extended error messages
AT CMEE=2
//Set GPRS APN Name
AT CGDCONT=1, IP , APN Name
Outgoing Connection COM3 - Tera Term VT
File Edit Setup Control Window Help
//Set packet size and timeouts on context 1-6
AT#SCFG=1,1,300,90,600,50
//Open GPRS context 1-6 with GPRS Username and GPRS Password. (This will return your ISP assigned IP address)
AT#SGACT=1,1, username , password
//Open Socket on Port Number at IP Address
AT#SD=1,0, Port Number, IP Address ,255,0
// Close GPRS context 1-6
AT#SGACT=1,0
AT CGDCONT=1, IP , APN Name
AT#SGACT=1,1, username , password
AT#SD=1,0,1024, 080.080.080.081 ,255,0
Incoming Connection COM3 - Tera Term VT
File Edit Setup Control Window Help
//Open GPRS context 1-6 with GPRS Username and GPRS Password
AT#SGACT=1,1, username , password
//Setup Firewall
AT#FRWL=1, IP Address , Subnet Mask
Europe Stories
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
04/08/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
04/07/2026
April 7 2026, 19:00 (PDT) Detective Conan: Fallen Angel of the Highway Opens in...
06/06/2026
Check Out Leading Monitor Brands
We'll have monitors of all shapes and sizes at GearExpo UK, so whether you're looking to upgrade or expand your set...
06/06/2026
Two Originals offerings join MPC line-up
Following on from their partnership announcement at NAMM 2026, Spitfire Audio and Akai Pro have announced the relea...
05/06/2026
Built from the same recordings as flagship library
Sonuscore's LUX Orchestral Strings has been met with widespread praise since its launch in late 2025,...
05/06/2026
High-end converter, interface & headphone amp upgraded
Said to represent the next evolution of RME's all-in-one reference converter concept, the all-new...
05/06/2026
Win a Soundgas Type 636P & Type G preamps
Soundgas, one of the UK's leading vintage and boutique audio equipment specialists have just announced the lau...
05/06/2026
New leadership of Technology Systems Division at Rohde & Schwarz On July 1, 2026, Hansj rg Herrbold and Andreas H gele will take over as Executive Vice Presid...
05/06/2026
Hitachi and Intel announced a strategic collaboration to explore opportunities t...
05/06/2026
05 Jun 2026
VEON's Kyivstar to Expand Digital Mobility Ecosystem with Acqui...
05/06/2026
RT Radio 1 Folk Awards to take place on Tuesday 10th November 2026, Vicar Street, Dublin
Moya Brennan, D nal Lunny, Mary Black and Christy Moore among previou...
04/06/2026
Steinberg DAWs now boast in-depth Tonalic integration
Celemony's innovative virtual session musician plug-in has just received an update that brings ARA...
04/06/2026
Get Hands-On With Over 20 Mic Brands
GearExpo UK is fast approaching, and if you've been looking for a chance to check out some new mics, then you'r...
04/06/2026
Combos feature new Amplifier Intelligence engine
Positive Grid's latest release sees the company introduce two new combo amplifiers that promise to offe...
04/06/2026
BackStory follows four Irish young people as they travel back to their parents' homelands
Modern Irish identity is enriched by cultures and influences from...
03/06/2026
Step sequencer-style panning tool revealed
Alongside their flagship self-titled sound-design platform, Sound Particles offer an array of creative effects an...
03/06/2026
Now features full H90 algorithm library
Eventide have announced the upcoming launch of the H9 Harmonizer Gen 2, a new and improved version of their hugely p...
03/06/2026
Significant discount available until 1 October 2026
Aim Audio have just announced a promotion that sees a significant discount applied to their Essence micr...
03/06/2026
Rohde & Schwarz to supply CERTIUM advanced communications system to Memmingen Ai...
03/06/2026
eds3_5_jq(document).ready(function($) { $(#eds_sliderM519).chameleonSlider_2_1({...
03/06/2026
RT confirms multi-channel and free to air coverage of the expanded tournament with enhanced digital features and the return of Total Football for young fans
S...
03/06/2026
03 Jun 2026
VEON to Release 2Q26 Earnings on July 31, 2026 Dubai and New York, June 3, 2026 - VEON Ltd. (Nasdaq: VEON), a global digital operator ( VEON or t...
03/06/2026
RT has today announced Heineken 0.0 as the broadcast sponsor of their FIFA World Cup 2026 coverage.
The sponsorship, brokered by Dentsu, will see Heineken 0....
02/06/2026
Musically intelligent soft synth gets upgraded
Scaler Music will be probably be best known to many for their music theory tools, but their product range al...
02/06/2026
Powerful new vocal-production tool announced
Described as a vocal performance station , Klevgrand's latest plug-in combines pitch-correction with harmo...
02/06/2026
Launched alongside Go Green sale extension
McDSP have just released the latest addition to their APB line-up, DC-2 Dual Compressor, and have also announced ...
02/06/2026
Create custom tools for Ableton Live 12 Suite
Ableton have just introduced a new open JavaScript toolkit that allows anyone to create their own custom tools...
02/06/2026
Now features full H90 algorithm library
Eventide have announced the upcoming launch of the H9 Harmonizer Gen 2, a new and improved version of their hugely p...
02/06/2026
Plus UAD Half Yearly Sale now live
The latest arrival to the Universal Audio range delivers a new native pitch-correction plug-in that's capable of deli...
02/06/2026
Rohde & Schwarz to present comprehensive performance, conformance and spectrum-m...
02/06/2026
BTL Laboratory becomes Taiwan's first test house with a CTIA Certification c...
02/06/2026
If you've kept up with this article series, you know by now where to start w...
02/06/2026
With new DSP configurations and flexible licensing options, Calrec is removing the barriers to virtualised audio, giving broadcasters the freedom to scale produ...
02/06/2026
02 Jun 2026
VEON Closes USD 1.4 Billion Bond Offering, Refinancing 2027 Notes A...
02/06/2026
Praise for series three:
The Times - sun-dappled pleasure
The Daily Mail - The Homes Counties' Charlie's Angels
The Sun - 4* this [is an] enjoya...
02/06/2026
Wuppertal June 2, 2026
Gudrun Scharler Appointed CEO of Riedel Networks The Riedel Group today announced the appointment of Gudrun Scharler as CEO of Riedel N...
02/06/2026
Trust has become a commercial issue With global advertising spend forecast to exceed US$1 trillion this year*, the commercial consequences of weak governance co...
02/06/2026
June sees Ireland's cultural calendar in full bloom, as RT Supporting the Arts showcases a vibrant and wide-ranging programme spanning music, theatre, visu...
02/06/2026
After The Traitors Ireland launched in 2025, Irish audiences proved to have a taste for the global hit reality show. This Bank Holiday Monday fans can indulge e...
01/06/2026
Category line-up & sponsors announced
Photo: Paul Clarke
The Production Music Awards (PMA) have announced that submissions are now officially open ahead of...
01/06/2026
New hybrid sample/synthesis instrument revealed
Excite Audio have just released the latest instalment in their Evolve series, which has been developed in co...
01/06/2026
Latest TONEX expansion captures three rare vintage amps
The newest addition to IK Multimedia's ever-growing TONEX line-up introduces a set of three incr...
01/06/2026
Musically intelligent soft synth gets upgraded
Scaler Music will be probably be best known to many for their music theory tools, but their product range al...
01/06/2026
Rohde & Schwarz Satellite Industry Days 2026 guided by the motto From Earth to ...
01/06/2026
Luxembourg, June 1, 2026 - SES, a leading space solutions company, and Viva, Mexico's ultra low-cost airline, launched fast and reliable multi-orbit satelli...
01/06/2026
Mardi 2 juin 14h00
FilmLight (ARRI), 10 rue Ren Boulanger, 75010 Paris
Rejoignez-nous pour d couvrir comment FLAPI (l'API FilmLight) peut transformer e...
01/06/2026
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...
29/05/2026
The days are getting longer, the temperatures are rising, and playlists are filling up for the season. With summer around the corner, Spotify's global edito...
Applicable Products Part number Description 
