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Omega 24 Channel Ethernet Data Logger with Embedded Web Server

24-Channel Ethernet Data Logger with Embedded Web Server
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Item# OM-240

Volume discounts available
Volume Discount Schedule
Quantity Price each
1-4 $3,641.80
5-9 $3,459.71
10-24 $3,386.87
25-49 $3,241.20
50-99 $3,168.37
100+ $3,095.53

In stock

Lead Time (If not in stock): 15 weeks
24-Channel Ethernet Data Logger with Embedded Web Server OM-240 OM-240
  • Omega Enterprise Gateway Compatible
  • 24 Differential, Independent Analog Input Channels, 2 Digital Inputs and 1 Digital Output
  • On-Board Web Server for Setup, Data View, and Diagnostic
  • Independent Thermocouples, PT100/200/500/1000, NTC, mV, mA, mV/V, Vibrating Wire

OM-240 Model Options

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Edit these specs to order a different model. Not all combinations are valid. Options compatible with previous selections will be in bold.

*Highlighted options are not compatible. Please select a different combination.

Measurement Type
Number of Measurements
Input Type
Maximum Samples
Data Interface
Max Sampling Rate
Additional Feature

OM-240 is a versatile, high accuracy “smart” data acquisition system. It provides 24 differential analog inputs, individually configured.

The Data Logger can be used in a wide range of applications, including HVAC, oil and gas, water quality, energy and building monitoring. Using OM-240 requires no additional configuration/analysis software package, as it is provided by an Embedded Web Server. Only a standard Web Browser (Firefox recommended) for configurations and data view. Logged Data is ready to be shown in a graphic “real time” mode (License required) or exported in a CSV file. Channel expansion provided by multiplexers. There are 8 terminal blocks (each terminal block can handle up to 3 sensors). The OM-240 is designed to work with 2 to 6-wire sensors. You can connect 2-wire sensors on each channel and read 24 sensors, or 4-wire sensor and read 12 channels. The system will order sensors depending on how many wires they use, placing 6 wires sensors first, 4 wires in the middle, and 2 wires last.

Once software configuration is done, clicking on “Wiring scheme” button on the web interface near the sensors will show how to connect the chosen sensor to the block physically. It shows “relative” position, so if you start connecting sensors from the first, you will not have to leave “unused” positions (except for the ground connection of every block, if not used). Multiplexers are needed if the total “wires” from sensors exceeds the 48 provided by the OM-240.

Applications including Oil/Gas Pipeline Monitoring, Building/Bridge Structure Health Monitoring, Engine Thermal Mapping Testing, Data Center Environmental Monitoring, and Energy Farm Monitoring, and etc.

Weight 980 g (2.16 lb)
Dimensions: 231 L x 138 W x 117 mm H (9.09 x 5.43 x 4.61”)
Material: Plastic and metal
Wiring: Removable screw terminal connectors
Analog Initialization (±10V range):
    Maximum Speed: 1.70 sec
    Standard Speed: 7.10 sec
Instrument Warm-Up: Depends on sensor configuration
Measurement (±10V range:
    Maximum Speed: 80 ms
    Standard Speed: 1.57 sec
Notes: Times indicated are not valid for vibrating wire measures Init analog phase is made only once before measurement cycle
Measure Frequency Selectable (Global or for Each Channel): 1 second up to 1 week
ADC: 24-bit (22 true bit) differential analog-to-digital converters, 5SPS to 1000SPS, 0-24 average function, auto-calibration and auto-range
Processor: ARM Cortex-M3 MCU with 1 MB Flash, 120 MHz CPU, ART Accelerator, Ethernet
RAM Memor 1 Mbyte RAM
Mass Storage: 2 GB SD card for data (about 5 Mega data points) and Web pages
Clock Accuracy: RTC (real time clock with battery back-up) temperature compensated
On-Board Sensors: Temperature (accuracy ±1%), measured inside the datalogger
Switched Output Power Supply: The voltage ‘V OUT’ is switched on and off under program control. V OUT is the unregulated input power supply ‘V IN’ (2 A Max)
Web Server on Board: (independent OS platform)
Acquisition Time Interva: Selectable from 1 second up to 1 week (depends on the number of channels acquired)
FTP client: To send data/alarms on an FTP server (SFTP not supported)
MAIL to send data/alarm: To max 5 email address (SMTPS / SSL not supported)
SMS to Send Alarms: To max 5 telephone numbers
Data Download: (measure, logs) in .csv file (compatible with Microsoft Excel)
Virtual Channels Management: For Math operations between channels
Thermocouple, RTD (Pt100, Pt200, Pt500, Pt1000), Thermistor, Current Loop, Current Transmitter, Voltage, Servo Inclinometer, Wheatsonte Bridge, Potentiometer, Vibrating Wire
Temperature Drift: < 10 ppm/°C, range -30 to 70°C (-22 to 158ºF)
Input Noise Voltage: 5.42 µV pp
Input Limits: ±12V
DC Common Mode Rejection: >105 dB
Normal Mode Rejection >90 dB
Input Impedance: 20 MΩ typical

Thermocouple Types: K, B, J, T, E, R, N, S
Resolution: 1 µV at FS for ±10 mV range;
10 µV at FS for ±100 mV range;
100 µV at FS for ±1 V range;

K-200 to 1370°C (-328 to 2498°F)±1,99 °C
B600 to 1820°C (1112 to 3308°F)±1,22 °C
J-200 to 1200°C (-328 to 2192°F)±1,04 °C
T-200 to 400°C (-328 to 752°F)±1,99 °C
E-200 to 1000°C (-328 to 1832°F)±0,93 °C
R-20 to 1760°C (-4 to 3200°F)±1,64 °C
N-260 to 1300°C (-436 to 2372°F)±1,24 °C
S-20 to 1760°C (-4 to 3200°F)±1,64 °C

RTD Types:
Resolution: 0.1°C
Power Supply: 1.2mA
Pt100/200/500/1000-195 to +847°C (-319 to 1556°F)0.17% FS

Thermistor Type:
3000 O @25°C, NTC
Resolution: 0.1°C
Power Supply: 0.05mA, 0.1mA, 1.2mA
3000 O@25°C, NTC-50 to 0°C±2 °C
(-58 to 32°F±3,6 °F
0 to 150°C±1 °C
(32 to 302°F)±1,8 °F

Power Supply:
5V, 10V, 20V, 24V DC*
±10 mV1 µV at FS0.01% FS
±100 mV10 µV at FS
±1 V100 µV at FS
±10 V10 mV at FS

Power Supply:
10V, 24V DC*
4 ~ 20mA1 µA at FS0.01% FS

4 ~ 20mA1 µA at FS0.01% FS

Power Supply:
5V, 10V, External (Max 10V)*
Minimum Bridge Resistance: 200 O
±10 mV/V0.001 mV/V at FS0.01% FS

Digital Output

One relay output (for alarm, etc.): volt-free closure (low voltage 30V, 2A)
Digital Inputs
Two opto-isolated digital inputs individually selectable for switch closure.
Max Input Voltage: 24V (max current: 10mA)
Min Input Voltage: 5V (max current: 2mA)
Measurement Rate: max frequency 1 kHz
Accuracy: 0.1 Hz
Electro-Mechanical Relays for Measuring Each Channel
Electrical Endurance: min 2 x 105 operations
Mechanical Endurance: 100 x 106 operations.
Circuit Protection (Gas Discharge Tubes) DC Breakdown Voltage (@100V/s): 75V
Tolerance of DCBV: ± 20%
Impulse Breakdown Voltage (@100v/µs ): 250V
Impulse Breakdown Voltage (@1kv/µs ): 525V
Overvoltage and Reverse Polarity Protection Short Circuit Protection on Every Output
Display & Keyboard
Small backlight graphic LCD 128 x 64 dpi with membrane keyboard for the minimal local management without the PC. Keyboard for starting a data acquisition scan, sequential display of the last stored readings for each channel (sensor ID, converted unit reading, unit of measure), device status, data download and firmware/Web pages update by USB pen drive, safe mode (back-up/format/restore internal SD card).
LAN Ethernet
10/100 Mbps, RJ45, Isolated
9-pin, DE9. DCE port for optional GSM/GPRS modem connection
Baud Rates: selectable from 9600 bps to 115.2 kbps
Default Format: 8 data bits; 1 stop bits; no parity
USB 2.0 pen drive only (FAT 32), 5 V 200 mA
RS485#1 AND RS485#2
Connection: 5 screw clamp port for max. No.254 Modbus RS485 digital bus sensors
Communication Interface: RS485 - Optoisolated
Communication Protocol: MODBUS RTU
Voltage ‘V OUT’: Switched on and off under program control. V OUT is the unregulated input power supply ‘V IN’ (1 A).
Power Supply Management: Always on or energy safe Every channel of each multiplexer board is completely independent.
Voltage (Power Supply): 10 to 30 Vdc (reverse polarity protected), max 5A
External Rechargeable Batteries: 12 Vdc nominal
Typical Current Drain (@12 Vdc)
Sleep Mode(MAX):
315 µA
ON: 62 mA - ON with Ethernet connected: 87 mA
ON with display: 115 mA
ON with display and ethernet connected: 142 mA
Analog Initialization: 115 mA
Measurement: 123 mA (with 12 mA @ 24 V sensor)
Operating Temperature: -30 to 60°C (display -20 to 60°C)
Storage Temperature: -40 to 85°C (display -30 to 80°C)
Relative Humidity: 80 %RH
Overvoltage Category: II
Pollution Degree: 2
Sound Levels: < 74 dBA
Maximum Height of Use: 3000 m (9800 ft)
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Do the Expansion modules allow thermocouple readings?

Asked by: Ken J
Hi Ken, thank you for your question. Yes, the multiplexer allows thermocouple inputs.
Answered by: DA Engineer
Date published: 2020-04-08

This is a similar model with less channels as 8, 12, 16 or 20?

Asked by: Anonymous
We will require more information to help on this question, please email the DAS team at DAS@OMEGA.COM
Answered by: Application Engineer PV
Date published: 2021-06-21

Is OM-240 compatible with Endress + Hauser TMR35?

Asked by: JP07
Thank you for your question. We will require more information to help on this question, please email the DAS team at DAS@OMEGA.COM
Answered by: Application Engineer PV
Date published: 2023-03-31

How many channels can you add to the base unit? I have a machine that is around 54. Adding the expansion unit would give me 48.

Asked by: Anonymous
Thank you for your question .Expandable Up to 384 Channels with Multiplexers
Answered by: Application Engineer PV
Date published: 2021-11-22

Does the OM-240 work with PX51 model pressure transducers, or only PT100/200/500/1000?

Asked by: RobertR
Thank you for your question. The OM-240 will be suited for a variety of different sensors like the PX51 which has a dc voltage or current output.
Answered by: Application Engineer PV
Date published: 2021-10-19

Can I acquire data from five analog sensors at one second interval (all sensors to be read at the same instant)? With one data sample consisting of time and readings from five sensors, how may data samples can be stored in the internal memory? Thanks

Asked by: SS2022
Thank you for your question. We will require more information to help on this question, please email the DAS team at DAS@OMEGA.COM&rdquo;
Answered by: Application Engineer PV
Date published: 2022-03-09

There is no GSM/GPRS modem available on the website, please guide to a store where it is available. thanks

Asked by: SS2022
Thank you for your question. We will require more information to help on this question, please email the DAS team at DAS@OMEGA.COM&rdquo;
Answered by: Application Engineer PV
Date published: 2022-03-09
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