ADU500 Battery Operated GSM Datalogger Unit




ADU-500 is an ultra low power, wireless RTU with data logging and alarming capabilities. The battery powered RTU incorporates three digital inputs, two analog inputs, one pulse counter input and multiple excitation options for powering measuring transducers. The device supports acquisition of up to 48 measurement channels, based on the popular SDI-12 communication protocol. ADU-500 uses an internal cell modem to automatically send data and alerts. The RTU is available for GSM/EGPRS and CDMA2000 network environments. A D-size Lithium Thionyl battery can provide autonomous operation for over 10 years.

The Infinite advantage

ADU-500 utilizes a dual processor architecture in order to combine extreme low power consumption with advanced processing and communication capabilities. A system controller (ultra low power MCU) performs measurement, data logging and alarm condition detection on a periodical basis. A powerful communication processor, switched on and off by the system controller, performs data processing and controls communications through the internal wireless MODEM. The result is up to 50% power saving comparatively to respective units of the competition, while performing the same tasks.

Measurements & Data Logging

The digital inputs are scanned by the system controller for detecting an alarm condition. Analog input gain, scaling and alarm limits are user definable. The analog inputs and SDI-12 sensors are sampled according to the user defined sampling rate. Sampling rate and sampling duration affect the battery life according to the transducer power supply requirements.

SDI-12 Serial Bus

SDI-12 is an asynchronous, ASCII, serial communications protocol that was developed for intelligent sensory instruments that typically monitor environmental data. The communication is achieved by digital communications. The addressing system allows data recorder to communicate with several microprocessor-based sensors over a single line. ADU-500 is compliant to the SDI-12 Standard Version 1.2 and supports extended commands for sensor configuration, in terminal mode. ADU-500 can collect data from several SDI-12 sensors for a total amount of 48 measurement channels.


ADU-500 supports acquisition from sensors with RS-485 interface, using the popular MODBUS ASCII protocol. Up to 10 measurement channels from several sensors are supported. 

Transducer excitation

The unit provides multiple excitation options for measuring transducers.

Alerting & messaging

SMS announcements include alert messages and periodical Status messages for verifying unit availability. The unit supports discrete alerting for several users. Message texts are user definable.

Data Transmission

ADU-500 supports periodical data transmission according to user defined parameters. The unit can send data via SMS to predefined users or to an internet server via FTP. 

Setup and Remote Configuration

The unit can be programmed locally through the serial port or remotely via SMS by using simple ASCII configuration commands. The command set features commands for configuring input alarm parameters, scaling parameters and alarm limits, timing parameters and defining user groups. ADU-500 can be remotely reconfigured by sending configuration commands to the unit during the periodical status message processing.



Power supply
Supply voltage Internal: 3.6V, 13Ah Lithium Thionyl battery (Saft LSH-20 recommended)
External: 9..24 VDC, 26VDC max
Supply current Continuous operation: 18μA, Messaging: average 50mA, 2A peak
Processing units
System controller Low power ARM 7 MCU
Communication processor ARM 9 processor
Data memory 128 KByte EEPROM
Digital inputs
Digital inputs 3, dry contact, 0-30VDC
Pulse counters 1, 2KHz, common with DI 3
Analog inputs
Input 1 (AI1) 2, Range: 0-5V/0-2.5V, 0-1V, 0-100mV, 12 bit resolution, Gain: 1-200, digitally set (PGA).
Input 2 (AI2) 2, Range: 0-2.5V, 0-1V, 0-100mV, 0-10mV, 0-20/4-20mA, 12 bit resolution, Gain: 1-200, digitally set (PGA).
Serial Bus features & options
SDI-12 48 channels, Support of extended commands in Terminal mode
RS-485, MODBUS 10 channels, MODBUS ASCII protocol
I2C Low power I2C sensors (OEM versions only)
RS-485 Low power sensors with RS-485 interface (OEM versions only)
Sensor excitation
Output 1 9VDC/250mA or 12VDC/200mA (Jumper selection)
Output 2 5VDC/200mA
Output 3 3.3V/250mA
Status & Alarm SMS
Data FTP or SMS
Wireless modem Quad Band GSM/EGPRS (850/900/1800/1900MHz) or CDMA2000/1XRTT
RF connector SMA Jack
Serial interface RS232C, up to 115 kBit/s
Temperature -40°...65°C, operating
Indications 2 LED, Network status, Operation status
Dimensions 130 x 130 x 75 mm
Protection IP66
Weight 0.5 kg (without battery)