DT80G - Data Logging for geotechnical applications

Product Description

Supporting vibrating wire sensors the dataTaker DT80G GeoLoggeris ideal for all geotechnical data logging applications. ThedataTaker GeoLoggers have built-in vibrating wire support providingideal data acquisition and monitoring solution for the engineerworking in the geotechnical environment. The low cost, low powerdataTaker DT80G is extremely versatile and easy to configure forcommunications, data capture and data analysis. View the data inreal time or store up to 5 million data points. Data storage andretrieval can be achieved via USB memory stick, FTP, cell phone,Modbus for SCADA, Ethernet or Web.


Supports vibrating wire sensors, including

  • Geokon
  • RST Instruments
  • Slope Indicator
  • Soil Instruments
  • and more...
  • Web Interface
  • Modbus for sensors and SCADA connection
  • Up to 15 Analog (± 30V) sensor inputs
  • Expandable to 300 analog inputs
  • 12V and 5V power output


Additional data logger solutions for specific applications:
DT85G, 5-15 analog, 12 digital channels
DT85GM, 16-48 analog, 12 digital channels, with integratedmodem

Technical Specification

Analog Inputs
The maximun number of inputs depends on sensor wiring configuration. Sensor configurations may be mixed.
Two wire with one shared terminal: 12
Three and Four wire: 4

Multiplexer (Input Selector)
Relay Multiplexer – provides isolation between inputs
Input impedance: 100K, 1M or >100M, programmable
Common mode range: ±3.5V or ±35V on 30V range

Sampling for accuracy and noise rejection by integrating over 50/60Hz line period
Maximum sample speed: 25Hz (up to 70Hz without noise rejection)
Effective resolution: 18 bits
Linearity: 0.01%
Common mode rejection 30mV range: >90dB
Line (50/60Hz) series mode rejection: >35dB

Sensor Excitation
Each channel: 4.5V, 250µA or 2.5mA or Switched external supply.

Sensor Support
Supports a wide range of sensors including, but not limited to, those listed below. A wide range of sensor scaling and linearising facilities is provided including polynomials, expressions and functions.

Types: B, C, D, E, G, J, K, N, R, S, T
Calibration standard: ITS-90

Materials supported: Pt, Ni, Cu
Resistance range: 10 to 10K

Monolithic Temperature Sensors
Types supported: LM34 - 60, AD590, 592, TMPxx

Bridge Sensors
Configurations: ¼ , ½ & full bridge
Excitation: voltage or current

4-20mA Current Loop
Shunt value: 100. to a shared common or external shunt 20. – 200. resistor

Digital Channels
Digital Input/Outputs
Number of channels: 8 Bi-directional channels for state & count input or state output.
Input Type: 8 logic level (max 30V). Measure state or low speed counts (max 10Hz) Low speed counters do no function in sleep mode.
Output Type: 4 with open drain FET (30V 100mA), 4 with logic output.

Relay Output
1 latching relay (30vdc, 1A max)

Dedicated Counter Inputs
Number: 4 high speed counters or 2 phase encoder(quadrature) inputs. 100kHz max
2 Counters have 10mV sensitive inputs for magnetic pick-ups.
Size: 32 bit

Serial Sensor Channel
Modes: RS232, RS422, RS485
Handshake lines: RTS, CTS

Baud rate: 300 to 115200
Programmable prompt string Data parsing allows multiple assignments to variables

Calculated Channels
Combine values from analog, digital and serial sensors using expressions involving variables and functions.
Functions: sin(), cos(), tan(), asin(), acos(), atan(), abs(), sqrt(), average, maximum, minimum, time of max, time of min, variance, integral, histogram, rainflow (fatigue analysis)

Condition: high, low, within range and outside range
Delay: optional time period for alarm response
Actions: set digital outputs, execute any dataTaker command, transmit message

Scheduling of Data Acquisition
Number of schedules: 11
Schedule rates: 10ms to days

Data Storage
Internal Store Capacity: 64MB = approx 5,000,000 data points
Removable USB store device
Types: compatible with USB 1.1 or USB 2.0 drives, e.g. Flash drive.
Capacity: approx. 90,000 data points per megabyte.

Communication Interfaces

Ethernet Interface: 10BaseT
Protocols: TCP/IP (UDP, FTP)

Speed: 300 to 115k baud (57,600 default)
Handshake lines: DCD, DSR, DTR, RTS, CTS
Modem support: auto-answer and dial out
Protocols: PPP, TCP/IP (UDP, FTP)
USB: USB 1.1, 12Mb/sec – virtual COM port.

Display and Keypad
Type: LCD, 2 line by 16 characters, backlight.
Display Functions: channel data, alarms, system status.
Keypad: 6 keys for scrolling and function execution
Status LEDs: 3 for sample, disk and attention.

Firmware Upgrade Via: RS232, Ethernet, USB coms. or USB disk.

Real Time Clock
Normal resolution: 200µs
Accuracy: ±1 min/year (0°C to 40°C), ±4 min/year (-40°C to 70°C)

Power Supply
External voltage range: 10 to 30Vdc

Power Consumption

12 V and 5 V power output
Normal mode: 5W (15V 330mA)
Charging flat battery: 12W (15V 800mA)
Sleep mode: 3mW (500uA from Internal 6V battery)

Internal Main Battery
Voltage (Capacity): 6V (1.2AHr) lead acid gel cell
Operating time: continuous sampling: 1 hour
10 minute sampling: 8 days
1 hour sampling: 21 days

Memory and Real Time Clock Battery
Voltage (Capacity): 3.6V (400mAHr) lithium, 1/2 AA

Physical and Environment
Construction: Powder coated zinc and anodized aluminum
Dimensions: 181 x 136 x 63mm
Weight: 1.5kg (4kg shipping)
Temperature range: –45°C to 70°C *
Humidity: 85% RH, non-condensing

*reduced battery life and LCD operation outside range –15°C to 50°C


Related Products