Applicable Products Part number Description
ZETA-NLP-LTE1 (EU) Ultra Low Power European LTE Cat 1 Modem
ZETA-NLP-LTEM (GL) Ultra Low Power Global LTE Cat M Modem
Objective Power consumption is one of the key requirements of any Wireless IoT application.
A significant contributor to power consumption in such systems is the Cellular modem.
This application note shows how to set Siretta ZETA NLP modem in ultra-low power mode for reduced energy consumption.
Solution ZETA-NLP Ultra Low Power Mode The ZETA-NLP has a special mode of operation which forces the unit to drop down to an ultra-low power state where the modem is still operational and registered on the network but is functionally asleep. This allows for the modem to remain connected to the network and be ready to send and receive data using a fraction of the energy.
This ultra-low power state is achieved by setting the following AT command to the modem:
COM3 - Tera Term VT
File Edit Setup Control Window Help
AT CFUN=5
OK
Ultra Low Power Control Signal To control the power state of the modem from low power to ultra-low power it is necessary to use a special control signal in the RS232 serial port.
The control signal is called Data Terminal Ready (DTR) and is available on the RS232 serial port on pin 4 as shown in the table below.
Once the CFUN=5 command has been issued then the modem is ready to enter ultra-low power mode. To activate low power mode and put the modem in to a dormant state the DTR line must be de-asserted on the serial port. When the device has entered ultra-low power mode the CTS line will be de-asserted indicating that the device has gone into ultra-low power state. At this point the serial port is also deactivated, and the modem will not respond to AT commands and will appear to be OFF.
To bring the modem back to normal power state and communicate with the modem again it is necessary to assert the DTR line and the modem will leave its dormant state and become fully active again for normal operation. When in the dormant ultra-low power state an incoming call request or incoming SMS will force the modem to enter its full power mode and the modem is able to be used as normal.
Pin Name Usage Status Direction
1 DCD Output from UART that indicates the carrier 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
This mode allows the modem to consume little current whilst it is not in use but be available for use locally by asserting the DTR line. The modem power ON and power lines will remain active throughout and can also be used to turn the modem completely OFF.
DTR Control Software To control the DTR line on the modem and communicate with the AT command interface on the RS232 serial port it is necessary to use Terminal software which controls the DTR line. Siretta has tested the ZETA modem family with several terminal emulator applications which support DTR and RTS control signalling. Two recommended applications are shown below:
Realterm (Download Link)
Telit AT Controller
Ultra Low Power Receiving Data In the ultra-low power state, a special provision must be catered for when data is received from a connected socket to be output over the serial port.
In this mode it is necessary to run the serial port in the following state:
Enable hardware flow control with AT&K3
Enable low power mode by issuing AT CFUN=5
Setup a socket connection and establish an active connection
Enter ultra-low power state by de-asserting DTR control line
De-assert RTS line
Wait for specified timeout to check for incoming data
When the timeout has expired, to check for data over the connected socket follow the procedure below:
Assert DTR line to disable low power state and activate full serial port
Assert RTS line to receive full buffered data over serial port and wait for all data to be received
When all data has been received de-assert RTS line
De-assert DTR line to re-enter low power state and wait for the specified timeout to receive further data.
NOTE - While there is no data pending reception from the cellular network, the modem does meet the published low power consumption figures. However, if there is data pending from the cellular network, then the modem power consumption rises to approximately 5mA at 12V until the data transfer process has completed and low power state is re-entered. The modem does not automatically enter the full power state when there is pending cellular network data, so the connected application is required to periodically poll the cellular network. If there is pending data from the cellular network, this will immediately start to be received over the serial connection.
Once the data transfer is complete, the modem can be put back into the low power state where it will meet the published power consumption figures. The shorter the check interval, the less time will be potentially spent at the higher 5mA current consumption. The longer the check interval the less power will be used checking for received data from the network. Choose this check interval to match the requirements of your system.
Demonstration of Solution Testing Ultra Low Power Mode using an Outgoing Socket Connection COM3 - Tera Term VT
File Edit Setup Control Window Help
//Set extended error
Europe Stories
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
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...
01/05/2026
January 5 2026, 18:30 (PST) NBCUniversal's Peacock to Be First Streamer to ...
01/04/2026
January 4 2026, 18:00 (PST) DOLBY AND DOUYIN EMPOWER THE NEXT GENERATON OF CREATORS WITH DOLBY VISION
Douyin Users Can Now Create And Share Videos With Stun...
28/01/2026
Music discovery should feel intuitive and personal. That's why we're continuing to give you more control, so you can ask for what you want, shape what y...
28/01/2026
Today, Charlie Hellman, Spotify's Head of Music, shared the following note on the Spotify for Artists blog that the company paid out more than $11 billion t...
28/01/2026
As demand for more complex live sports coverage grows, Balkan broadcast specialist MVP has upgraded its flagship HD1 progressive OB truck with the installation ...
28/01/2026
Luxembourg, January 26, 2026 - SES S.A. ( SES or the Company ), a leading space solutions company, acknowledges the credit rating action announced by Fitch to...
28/01/2026
28 Jan 2026
VEON Notes Kyivstar Group Publication of Selected Full Year 2025 Fi...
28/01/2026
Rohde & Schwarz to host 2026 edition of its online event Demystifying EMC Rohde & Schwarz invites the global EMC community to join a crucial discussion on pre...
28/01/2026
Stadtwerke Wolfhagen Modernize Customer Management with AEP.energysuite from Arv...
27/01/2026
Click for Japanese version
Tokyo, Japan - January 27, 2026 - Akamai Technolo...
27/01/2026
Today, Spotify is proud to support our partner Backline, an industry-leading men...
27/01/2026
With nearly 29 million monthly listeners and clear momentum on Spotify, Net n Ve...
27/01/2026
eds3_5_jq(document).ready(function($) { $(#eds_sliderM519).chameleonSlider_2_1({ content_source:......
27/01/2026
New agreement for uninterrupted UHF connectivity for Australian Defence Force through 2033, With Options Extending to 2041
Luxembourg, January 13, 2026 - Satel...
27/01/2026
Tuesday 27 January 2026
SNL UK creative team expands as Pauli Lovejoy, Annie Ha...
27/01/2026
RT Supporting the Arts is delighted to support a dynamic programme of cultural events taking place across Ireland this February. From visual art, film, music, ...
26/01/2026
Music videos play a huge part in how fans connect with their favorite songs, but...
26/01/2026
Wuppertal January 26, 2026
Riedel and Media Tailor Deliver Unified Broadcast a...
26/01/2026
26 Jan 2026
VEON Unveils the New Beeline Uzbekistan Network Operations Center, ...
26/01/2026
Bookish is created by and stars Mark Gatiss
Images available HERE
Following th...
26/01/2026
Monday 26 January 2026
New Sky Original Series explores Entertainment Juggernaut, The X Factor
Sky today confirmed it has greenlit a premium, definitive docum...
26/01/2026
Monday 26 January 2026
Sky confirms major investment to transform Livingston ca...
26/01/2026
Software for Stable Data Management and Lasting Business Success in Uncertain Ti...
26/01/2026
RT is today publishing a statistical summary of the Register of External Activities for the third quarter of 2025.
The RT Register of External Activities com...
24/01/2026
RT and Virgin Media Television kick off comprehensive free-to-air coverage of t...
23/01/2026
Staines-upon-Thames, UK, 29 July, 2025 - Yospace, the global leader in Dynamic A...
23/01/2026
Spotify's annual Best New Artist celebration honors the rising stars whose talent, creativity, and dedication have propelled them to the music industry'...
23/01/2026
Paramount is transforming its operations by unifying the media supply chains of their top brands into a scalable global pipeline.
This transformation enhances ...
23/01/2026
Every delay costs. When a subtitle fails QC, even the smallest issue can mean missed deadlines, extra vendor costs, or frustrated teams. The new Accurate.Video ...
23/01/2026
Find out where Sare and Suze are now on RT One and RT Player Thursday 29 January at 10.15pm
Hit drama SisterS, created by, written by and starring real-life ...
23/01/2026
Friday 23 January 2026
Sky appoints Lisa Clark as Commissioning Executive for SNL UK
Lisa Clark headshot
PNG (468KB)
Lisa Clark joins Sky as Commissioning E...
23/01/2026
RT is delighted to announce that the RT and F s ireann / Screen Ireland supported short film Retirement Plan has been nominated for Best Animated Short at th...
22/01/2026
Last November, Ed Sheeran returned to his musical roots for an intimate, one-nig...
22/01/2026
Every delay costs. When a subtitle fails QC, even the smallest issue can mean missed deadlines, extra vendor costs, or frustrated teams. The new Accurate.Video ...
22/01/2026
Thursday 29 January 9:35pm on RT 2 and RT Player
The dating show returns with something old, something new and a dater you may already know
Thursday evenings...
22/01/2026
Rohde & Schwarz, Qualcomm, and Motorola demonstrate successful 5G Broadcast comp...
22/01/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
21/01/2026
Wednesday 21 January 2026
Backing Britain on the global stage: Sky becomes an o...
21/01/2026
Fox Corporation Executives to Discuss Second Quarter Fiscal 2026 Financial Resul...
21/01/2026
Baselight v7 brings colourists and post-houses smarter mattes, faster workflows and deeper control
FilmLight, known for its detailed colour toolset and longsta...
21/01/2026
RT News is pleased to announce the appointment of Jackie Fox as its new Washington Correspondent. Jackie is a multimedia journalist with RT News and has repor...
19/01/2026
Monday 19 January 2026
Sky News reinvents News at Ten for the modern audience with The Wrap
Sky News today announces The Wrap, a bold evolution of its 10pm ou...
19/01/2026
DPA Microphones is striking a new chord in piano miking with the debut of its DPK2015 Piano Stereo Kit, an out-of-the-box, plug-and-play miking solution that ta...
19/01/2026
DPA Microphones will present its 4099 CORE Instrument Microphone and redesigned...
19/01/2026
Trianel relies on Arvato Systems for future-proof data center operations
Moving to the cloud: Arvato Systems implements extensive IT migration project
Migrat...
19/01/2026
Celebrating 21 Years of the RT Choice Music Prize
RT Choice Music Prize
In association with IMRO and IRMA
Irish Album of the Year 2025 - Shortlist Announce...
18/01/2026
January 18 2026, 21:30 (PST) Dolby Cinema Arrives in Bengaluru: Dolby Laborator...
Applicable Products Part number Description 
