GT900 110 - 343 - 686

Industrial GSM/GPRS device


  • Industrial GSM/GPRS 850/900/1800/1900 MHz communication/telemetry devices
  • Based on Simcom SIM900D module
  • Three different platforms based on number of inputs and outputs: 6/3/0* analog voltage/current inputs, 6/3/1* relay outputs with NO contacts and 8/4/1* optocupler inputs *see table of hardware platforms
  • RS232 DCE serial interface
  • Digital inputs and relay outputs are galvanicly isolated allowing easy implemetation into every system
  • Device state indicated by four LED diodes
  • Wide power supply range 8 to 30V DC
  • DIN 35mm rail mounting

Functionality of the following devices is available in three different platforms, 110, 343 and 686, with different hardware resources, shown in Table of hardware platforms.

Analog inputs can be configured to work as voltage or current inputs. Relay outputs have large current capacity, so they can be used to directly drive 220V consumers and they can also operate in pulse mode.

Devices can be configured by Decode GSM Utility free software through RS232 connection, and afterwards setup of device perimeters is possible. This device parameter setup can also be done via SMS.



SMS Reporter is industrial GSM/SMS telemetry device which uses GSM network for transferring commands, alarms and data by using SMS messages.


SMS Reporter handles remote reading of analog and digital inputs and managing relay outputs by sending SMS message. Moreover, SMS reporter can be adjusted to send SMS messages on each state change of analogue and digital input. Each analogue and digital input has SMS table for up to 8 different SMS numbers.



GPRS Router is industrial GSM/GPRS communication device which uses GSM network for transferring commands, alarms and data. Basic function of device is to manage transfer of industrial protocols over GPRS and to connect remote PLCs to SCADA programs over the VPN/GPRS network. Therefore, in addition to classic GPRS terminals, this device enables routing of fixed IP addresses and sending data from remote locations to center. Currently, GPRS Router supports Modbus and OMRON Hostlink protocols, but it can be adjusted to support other industrial protocols based on asynchronous serial communication. It is also possible to configure the device as MODBUS slave by allocating internal address.


GPRS Router handles transfer of asynchronous serial data between two devices in point to point configuration, or between more than two devices in star configuration (replacement for master-slave RS485 network). Device can be configured to work as master or slave via command mode. Master can establish connections with slave modules by using dynamic route selection from routing table. Slave modules can have one or more fixed routes to master module (also placed in routing table), selectable by setting code combination on four digital inputs. By allocating internal address to slave device, internal MODBUS slave is activated. In other words, slave is then behaving like RTU.




GSM Key is a GSM relay management device that uses GSM network for managing one relay output with free call. Managing of relay output is allowed to numbers defined in user list that can contain up to 200 GSM numbers.


GSM key enables remote management by one free call using one relay output. Device can be configured to send SMS about status changes on digital input.

SMS gateway


SMS Gateway is industrial GSM/SMS communication device that uses GSM mobile network for distribution of commands, alarms and data, using SMS messages.


SMS Gateway enables remote communication with remote control stations (equipped with PLC controller) by sending SMS messages. This enables remote management of control station, and, on the other side, it enables control station to notify users about changes of states and alarms. SMS Gateway can be adjusted to send SMS messages when state on digital input is changed. It is possible to enter up to 8 different numbers for digital input. Relay output can be managed by sending adequate SMS command.


PlatformRelay outputsOptocoupler inputsAnalog inputs


Quad-Band GSM/GPRS 850/900/1800/1900 MHz
Compliant with GSM phase 2/2+ standard
Output powerClass 4 (2W at 850/900MHz)
Class 1 (1W at 1800/1900MHz)
SIM cardMini SIM, 1.8V/3.0V
Serial interface RS232DCE configuration, DB9 female
Serial baud rate in command mode9600 bps, 8N1
Analog inputs6/3/0* inputs with conjoint bulk, with adjustable software:
- current inputs 0-20mA or 4-20mA
- voltage inputs 0-5V or 0-10V
Digital inputs8/4/1* inputs with conjoint bulk, separated with optocouplers
Nominal 12V DC – 24V DC max 30V DC
Logic 0 – Input voltage < 4V DC
Logic 1 - Input voltage >5V DC
Counting mode: 0 - 65535 pulses
Relay outputs6/3/1* relays with NO contacts, 5A, 30V DC / 250V AC
Antenna connectorSMA female, GSM 50Ω antenna with 3m cable included
LED indicationPower ON, GSM ON, Ready, Busy
Power supplyDC power supply, from 8 to 30V
Power supply connectorPluggable screw clamp 5mm, 2.5mm2
Power consumptionStandby 0.2W, max 3W
Dimension35x85x58 mm; 70 x 85 x 58 mm; 105x85x58mm (without connection blocks)
Weightcca 150g
Temperature range-20°C to +75°C, 0 to 95% RH (non condensed)
MountingDIN 35mm rail

Ordering information

GT900 - 110104161 relay output, 1 digital input€165


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SKU# 10416

GT900 - 343104173 relay outputs, 4 digital inputs, 3 analog inputs€200


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SKU# 10417

GT900 - 686104186 relay outputs, 8 digital inputs, 6 analog inputs€250


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SKU# 10418

*Minimum functionality kit needs to include the device, appropriate power supply and GSM antenna. Please note that all accessories are sold separately.

Buy from distributor


ANT-GSM-R21760GSM Rod antenna, 2.2 dBi, SMA, quad band€5
ANT-GSM-S21757GSM Swivel antenna, 2.2 dBi, SMA, quad band€6
ANT-GSM-M23266GSM antenna, Magnetic mount, cable 2.5m, 2.2 dBi, SMA, quad band€7
PS-1212-AD10261AC/DC adapter, DC12V 12W, AC100-240V 50/60Hz]€8

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SKU# 10261
PS-2415-DIN23601Power supply, DIN rail mount, DC24V 15W, AC85-264V 50/60Hz


CB-DB9MF-2M21745Serial Cable Assembly 1.8~2m, DB9 Male to DB9 Female


ENCL-DIN35-H22348535mm DIN Rail Holder, Plastic


Product Documents