WM Systems WM-E3S Elster As Smart Meter Installation Guide
Document specifications
This documentation was made for the installation and configuration of the WME3S® modem.
| Document Version: | REV 1.2.9 |
| Hardware Type/Version: | WM-E3S® (TELIT) Modem for electricity metering |
| Hardware Version: | V 4.18, V 4.27, V 4.41, V 4.52 |
| Firmware Version: | V 5.3.32 |
| WM-E Term Software Version: | V 1.4.0.15 |
| Pages: | 26 |
| Status: | Final |
| Created: | 09-01-2025 |
| Last Modified: | 09-01-2025 |
Chapter 1. Introduction
WM-E3S ® is an integrated modem unit PCB. It is suitable for remote reading of electricity meters.
You can save money by using our modem, because furthermore there is no need of manual readout of the meter systems.
Wireless communication
The modem can be ordered with different cellular module types:
- LTE Cat.4 / 3G / 2G module
- LTE Cat.1 module with 2G “fallback”
- LTE Cat.M / Cat.NB module with 2G “fallback”
Over the LTE 4G communication, all versions of the device having a 2G mode or 2G “fallback” feature, therefore in case of outage/inaccessibility of the LTE 4G network, it is further communicating on the 2G network.
Depending on the client’s needs, the modem can be set to which network it uses (e.g. only LTE 4G or 3G, etc.) or the best available network (Auto mode). I
t can also be set that only GSM-CSData connection – e.g. in the case of a CSData supported module, by initiating CSData calls.
The modem supports multi-operator SIM and the roaming feature.
The device provides a SIM-card independent- and mobile operator independent solution.
Design and installation
This modem was especially developed for Honeywell® / Elster® AS3000, AS3500 electricity meters. Alternatively it can be used with Honeywell® / Elster® AS220, AS230, AS300, AS1440 meters also.
The device can be installed under the sealed terminal cover of the electricity meter without replacing the seal certifying the first verification or the non-destructively sealed measuring housing. The modem can be connected to the meter by sliding into the meters’ communication module slot and can be sealed.
Thus, the modem presents a compact solution, the dimensions of the meter will not change if a modem if fitted or not. This solution offers the possibility of future upgrade of the electricity meter with a communication module and is ideal for installations where there is restricted assembling space.
Operation properties, features
The modem is thus suitable for retrieving current and stored measurement data, reading recorded event log and load curve data, and reading and remotely managing meter parameter files.
The modem can be used with “push” mechanism, thus the modem can initiate the communication with the HES (smart metering center/server) periodically at a preprogrammed time interval or triggered by an alarm (power outage, cover removal, reverse run, etc.).
The device can be accessed remotely via the mobile network and is capable of sending data over the Internet using an APN.
The modem is basically prepared for transparent data transmission between the metering server or metering service provider, with CSData call (only for 2G network setting!) And via mobile internet (TCP) connection (“PULL” mode) suitable for electricity meter registers. and remote reading of load curves, use of standard reading commands, remote reading and modification of the meter / parameters, updating of the meter application firmware.
Power source and power outage
The device can be powered from the meter’s internal mains connection (by 230V AC voltage).
Supercapacitor
The modem is also available with a power outage protection by an optional super capacitor component, which allows to continue the modem operation in case of minor power outage(s).
In case of a power outage, the super capacitors will discharge by time, and the modem will shut down. When the power supply returns, the modem restarts and sends data over the cellular network, and the capacitor components will be charged).
Configuration and firmware refresh
The modem can be configured locally via RS485 port or optical port, remotely with a CSData call (only if you use a setting that also uses a 2G network!) Or via a mobile internet (TCP) connection, and its firmware can be updated. The modem is configurable via TCP port remotely (or via local serial connection) and operating on the wireless network by configuring the APN, username and password (APN information is provided by your local mobile operator).
All settings can be configured with our administration tool (the WM-E Term® software), but also API available so our partner can easily adapt their current administration environment.
The configuration is possible by one device or for a group of devices.
The WM-E Term® tool is password protected and user management is also possible.
The configuration tool requires Windows® platform to run. It is available in English and some local languages as well (as French, German, Spanish, Czech, etc.).
Security
The product’s firmware is encrypted and prevented against to upload firmware or data from other devices. The modem cannot be upgraded by any other 3rd party firmware – it’s safe.
The control port of the modem is encrypted by AES (by option), or can be ordered with TLS protocol usage.
The external flash- and the internal flash content of the device are encrypted.
All security protocols can be activated/deactivated by authorized client.
Status and notification
The modem is continuously monitoring the mobile network and device communication health, and can send status information (signal strength, QoS).
By the configured features, the device is able to send SMS alarm notification, Last Gasp notification – depending on the used cellular network and mobile operators (if the SMS notification is not disallowed on the network, then it can be used). The LastGASP SMS notification feature is available by some models for case of reporting the occurred possible power outages.
Certification
The modem is accomplishing with CE standard (Radio Equipment Directive (2014/53/EU)) and safety directives (EN 60950-1 / EN 62368-1) and RoHS declaration and has CE certification
Chapter 2. Assembling instructions
Connectors, interfaces
- Mains connector
- Push button
- Internal data connector (to the meter)
- SIM card holder (push-insert, mini SIM, 2F
- Connector (for factory purposes only)
- SMA antenna connector
- U.FL antenna connector
- Telit LTE module
- Recharegeable backup battery
- Power supply unit
- 6pcs Status LEDs
Inserting the SIM card
Insert an activated SIM card into the push-push SIM card slot (4). The SIM card is easily replaceable by pushing the inserted SIM card when it is necessary.
Connecting the modem unit PCB to the meter
Take off the Honeywell® / Elster® AS3000, AS3500 meter’s communication module plastic case by releasing the screw from the top middle part of the housing.
Inside the communication unit’s case mount the SMA-M antenna interface connector (6) on the housing. Then fasten it with the SMA connector’s screw nut.
Now snap the modem unit PCB into the communication module’s plastic housing by sliding it through the guiding rails of the case until you hear a click sound.
Beware to place the modem unit PCB orientation into the slot. The 12-pins data connector (3) can help You to find the right position (upper right in the figure)
The internal interface connector (3) is close to the SMA antenna connector (6) (right top side on the picture).
The PCB must be pushed until it is locked and fixed into the communication module’s case. At the middle of the modem unit PCB there is whole that permits to the fixation hook of the communication module’s housing to fix and holds back the modem unit PCB. When you want to remove the modem unit PCB, you must force the hook to release the PCB.
Now we can connect the communication module to the meter by sliding the communication unit into the meter housing.
The communication interface (3) and the mains connectors (1) must be connected to the connector pairs from the meter housing.
You will found, that the meter and communication module housing upper right edge is a rounded (radiused) as a sign of the perfect slide fit adaptation.
After assembling and turning on the meter the modem will be powered and its operation is confirmed by the LED signals (11).
Antenna connection
For proper operation of the communication module, it is necessary to getting sufficient cellular network signal strength.
Where the signal strength is strong it is possible to use internal antenna, for areas with poor reception mount an antenna to the SMA-M connection interface of the device (through U.FL antenna wire connectors).
Status LED signals
The LED numbering can be seen at LED labels on the modem panel: from left to right in order: LED1 (blue, left), LED2 (red, right), LED3 (green, center) then LED4, LED5 and LED6.
Factory default LED signals:
| LED identifier | Events |
 GSM / GPRS status |
|
 SIM status / SIM failure or PIN failure |
|
 E-meter status |
|
 E-meter relay output status |
|
 M-Bus status |
|
 Firmware status |
|
*LED 4 operation is available only in case of presence of the WM-E3S CIR version.
** LED 5 operation is available only in case of presence of the MBUS version.
Further status LED signals (can be configured as well):
| LED identifier | Events |
| Network status and access technology |
|
| Meter status with IEC polling |
|
| AMM (IEC) client state |
|
meter starts communicating, the LED flashes 1x per second.** The EI client is a transparent TCP channel outgoing from the modem to the EI server
Push operation method
The complete readout and data sending mechanism to the center and the other direction for the configuration and maintenance tasks can be realized on the defined paths.
The modem does not operate continuously on the network.
Therefore, there is another option and meter data sending mode to initiate a remote readout automatically in the pre-defined intervals. Anyway, it is also possible to start the data sending in case of different events (e.g. removal of meter cover, incoming SMS message from the center).
In this situation the modem is connected to the mobile data network only during the time of the data transmission.
The device needs to be connected to GSM network and ready to connect to GPRS, but without active IP connection
- Data Push – starting at predefined times
- The Data Push method triggers FTP file upload, plain text or encrypted.
- The unique filename and the file is generated automatically.
- The ftp function also requires an ftp server to receive data that is accessible from the currently used mobile network.
- The ftp must be set to passive mode.
- Unique file names are generated automatically.
- The file always consists of two parts, first a standard register read and then an event log (containing the events of the last 31 days).
- The readings shown as standard IEC format, including some ASCII control characters like STX ETX, etc. also.
- Alarm Push – starting when new event can be read from meter
- Alarm Push method triggers TCP sending of a DLMS WPDU contains the IP address,
- listening port number for transparent service, and the meter ID.
- Triggering with SMS
- GPRS connection can be activated remotely with a defined SMS from any call number.
- The SMS text must be left empty.
- After the SMS received, the modem will connect to IP network, and will be accessible as a IP server for a time period defined in the config file.
- Example config file will be provided with a 30 minutes setting.
LED operation during the CSD call
The CSD call consists of two parts:
- a.) We want to read / configure a meter in transparent mode
- b.) We want to perform a modem configuration / firmware update
To read / configure a meter in transparent mode:
- The LED configured for GSM / GPRS status will be lit continuously during CSD call.
- The LED that is configured for e-meter status will flash according to the CSD call status:
- It will flash every half second from the beginning of the connection to the end of the connection / If the measuring interface is not configured for a baud rate of 9600, the LED will be lit continuously from the beginning to the end of the connection
- After closing the connection, the LED will turn off
If you want a modem configuration / firmware update:
- The LED configured for GSM / GPRS status will be lit continuously during the CSD call.
- In this case, the other LEDs do not change due to the CSD mode.
Configuring from CSD connection
If the modem restarts due to an incorrect configuration, it is possible to access it with a CSD call. Its operation can be fine-tuned in the WM-E Term software with a value that can be specified in the PDP connection delay field in the APN parameter group. For more information, see Chapter 3.1 of the WM-E Term User Manual.
Automatic network reconnection
If the mobile network provider drops the modem from the cellular network due to the device’s network inactivity, there are available parameters if these are set, then automatic and periodical connection rebuild can be caused. If the network provider sends a message to the modem that the data connection has been lost, the connection will be restored automatically. If you do not send a message, you can choose from these two workarounds to follow:
- a.) Active mode – Use periodical ping, set the ping:
- For setting this, set the Watchdog parameter group’s ping parameters as Ping IP-address, Number of ping retries, Ping wait-time (for reply) and Wait-time (for next).
- If there is no ping response, it reconnects to the network after the time interval specified in the Seconds, GPRS connection closed and restored after this time parameter.
Attention! In case of frequent ping using, the data traffic will be higher, but the chances are higher that the device will remain on the cellular network.
- b.) Passive mode – If you don’t use the ping – set the connection retry:
- For setting this, use the Watchdog parameter group’s Seconds, GPRS connection closed and restored after this time parameter.
- Here you can define that after the network drops out the modem, how long does the modem wait before trying to reconnect to the mobile network again. Ask your mobile provider about the offered settings.
Attention! If there is less data traffic and there is no ping configured, the device may not stay on the network for a long time.
If you set this parameter to a low value that can cause frequent network reconnections.
Therefore, under no circumstances should you set this value lower than what your mobile service provider recommends. (e.g. there are mobile network providers that limit the number of times a modem can log on to the network in a given time)
Chapter 3. Modem Configuration
Configuration
During the configuration and connection, the power supply of the modem power supply is provided by the connected meter through the internal connector.
The modem must be configured by the WM-E Term® software by configuring its parameters which must be performed before the normal operation and usage.
Important! The WM-E3S® modem can be configured through meter’s RS485 connection, meter’s optical interface or via TCP connection settings.
Use the WM-E Term program for the configuration – use the WM-E Term User manual. Over the parameter settings of meter, modem and communication, etc., you can also test the modem communication by the configuration program.
For the proper communication of the modem, you have to configure the APN settings of the SIM – as PIN code, APN, username and password. These all can be configured by using the WM-E Term® software.
For the successful operation of the communication module it is necessary to have appropriate signal strength.
In places where the signal strength is strong it is possible to use internal antenna, for areas with poor reception mount an external antenna (50 Ohm SMA connection) to the antenna connector (3) of the device, which you can place inside even inside the meter enclosure (under the plastic housing).
If you want to readout the meter parameter values during the PC-modem connection you made, then you should select a different configuration port to the meter as TCP/IP or Optical or RS485 (Serial).
Configuring the modem by WM-E Term®
The Microsoft .NET framework runtime environment is required on your computer.
Download WM-E Term® to your computer from the following location using a browser: https://m2mserver.com/m2m-downloads/WM-ETerm_v1_4.zip
Then unzip the .zip file to a directory and execute the WM-ETerm.exe file.
The configuration software supports user account management and password change. You can log in to the program with a password! Follow the WM-E Term® configuration software’s User’s Guide!
The LEDs on the device always inform you about the current status of the modem.
For the operation of the modem cellular network communication and SIM card settings (such as APN, password, and account) are required.
In addition, be sure to review and save the transparent mode data speed functions in the WM-E Term program for the RS485 settings. In addition, you must send the configured configuration to the modem using the program – according to the configuration software’s User Manual document.
With the configuration software you can also update the modem’s firmware. Then the modem will restart and work according to the new settings.
WM-E Term User Manual:
https://m2mserver.com/m2m-downloads/WM-E-TERM_User_Manual_V1_97.pdf
Sending an SMS from the meter
Depending on the meter configuration, by using the modem, the meter can send SMS message corresponding to standard AT commands to the phone number which was configured at the meter side.
It is worth configuring this primarily for alarms and special events, according to the capabilities of the meter.
No other settings are required in WM-E Term®.
Signal strength
Check signal strength of the cellular network in the WM-E Term® software Device Information menu or by using the 
icon. At the end of the process, the current status information will be updated.
Check RSSI value (at least it should be yellow – which means average signal strength – or better if it is green).
You can change the antenna position while you will not receive better dBm values (the status must be readout again for refresh)
Power outage management – for supercapacitor expansion only!
If supercapacitors are presented on the PCB or on the additional expansion board, then the firmware of the modem will support the LastGASP feature. This means that in case of power outage the modem’s supercapacitor allows to operating further the modem for a short time (a couple of minutes).
In case of detecting the loss of mains/input power source, the modem generates a “POWER LOST” event and the message will be immediately transmitted as an SMS text to the configured phone number.
In case of recovering the mains/power source the modem generates the “POWER RETURN” message and sending by SMS text.
The LastGASP message settings can be enabled by the WM-E Term® application – in the AMM (IEC) parameter group part.
Restart the modem
There cannot be found a direct option for modem restart in WM-E Term. But it is very easy to push the modem to be restarted.
- Choose any parameter from the readout values.
- Change a parameter value
- Push to the
button. - Send the settings by Parameters Write
icon to the modem. - At the end of the writing process, the modem will be restarted.
- The restart of the device is signed by the LED3, which will be flashing quickly by green for 15 seconds. The starting requires 2-3 minutes while the modem will be available on its interfaces.
- Afterall, the LED will be operating ordinary as it is listed in the LED operation behaviour description.
Chapter 4. Support
If you have a technical question regarding the usage You can find us on the following contact possibilities:
Email: support@m2mserver.com
Phone: +36 20 333-1111
Support
The product has an identification void which has important product related information for the support line.
Warning! Damaging or removing the void sticker means the loss of product guarantee.
Online product support available here: https://www.m2mserver.com/en/support/
Product Support
The documents and information related on the product are available here. https://www.m2mserver.com/en/product/wm-e3s/
Chapter 5. Legal notice
©2025. WM Systems LLC.
The text of and illustrations presented in this document are under copyright.
Copying, usage, replication or publication of the original document or its’ parts are possible with the agreement and permission of the WM Systems LLC. only.
The figures in this document are illustrations, those can be different from the real appearance.
The WM Systems LLC doesn’t take any responsibility for text inaccuracy in this document.
The presented information can be changed without any notice.
The printed information in this document are informative only. For further details contact us.
Warning
Any fault or upcoming error during the software upload/refresh can lead to the device breakdown. When this situation happens call our specialists.
Documents / Resources
 |
WM Systems WM-E3S Elster As Smart Meter [pdf] Installation Guide V 4.18, V 4.27, V 4.41, V 4.52, WM-E3S Elster As Smart Meter, WM-E3S, Elster As Smart Meter, Smart Meter, Meter |