The OMB-DAQ-TC-RACK and OMB-DAQ-TC-RACK-EXP32 offer exceptional performance and accuracy for thermocouple measurement applications at a low cost per channel. Offering both Ethernet and USB ports, the OMB-DAQ-TC-RACK provides 32 channels of 24-bit resolution for medium channel installations. The OMB-DAQ-TC-RACK-EXP32 adds 32 high-precision channels to support larger installations. Accuracy is designed into the product with sigma-delta 24-bit ADCs, differential inputs, thermocouple-to-host isolation and cold-junction compensation (CJC) for each channel to reduce the effects of thermal gradients. With digital alarming notifications when a temperature exceeds programmed limits, the OMB-DAQ-TC-RACK and OMB-DAQ-TC-RACK-EXP32 offer the perfect solution for temperature monitoring applications including server rooms, refrigerated storage, and long-run test cells.
Specifications (Typical for 25°C (77°F) unless otherwise specified) These specifications apply to both the OMB-DAQ-TC-RACK and OMB-DAQ-TC-RACK-EXP32 unless noted otherwise. Thermocouple Input A/D Converter Type: Delta-Sigma A/D Resolution: 24-bit Number of Channels: 32 (64 when OMB-DAQ-TC-RACK is connected to OMB-DAQ-TC-RACK-EXP32) Filtering Options: 50 Hz or 60 Hz noise filtering, software-selectable Isolation Between Any Thermocouple Input Channel and Chassis Ground: 500 Vdc absolute max Channel Configuration: Software-selectable to match thermocouple sensor type Differential Input Voltage Range: ±78.125 mV Absolute Maximum Input Voltage (Between any Two TCx Inputs): ±25V (power on), ±25V (power off) Differential Input Impedance: 50 Hz Filtering, Power On: 26 M? 60 Hz Filtering, Power On: 20 M? Input Current: Open Thermocouple Detect Disabled: 2 nA Open Thermocouple Detect Enabled: 75 nA Common Mode Rejection: 50 Hz Filtering at DC and fIN=50 Hz: 110 dB 60 Hz Filtering at DC and fIN=60 Hz: 110 dB Noise Rejection: 50 Hz Filtering at fIN=50 Hz: 80 dB typ 60 Hz Filtering at fIN=60 Hz: 80 dB typ Input Bandwidth: 50 Hz Filtering: 22 Hz 60 Hz Filtering: 26 Hz Crosstalk Between Any Two Thermocouple Inputs: -90 dB Sample Rate: 3 Hz max (per channel); the enabled thermocouple inputs are continuously converted at the maximum A/D converter rate Common Mode Voltage Range: TCx Channel to TCx Channel: ±1.40V TCx Channel Relative to Chassis Ground, fIN = 60 Hz: ±3.5 Vac p-p TCx Channel Relative to Chassis Ground: ±48 Vdc When thermocouple sensors are connected to different common mode voltages, the channels with floating thermocouples sensors are biased to approximately the average value of the applied common mode voltages. Each of the applied common mode voltages must then be less than or equal to the average common mode voltage ±1.40 V or [CMVapplied = (CMVaverage ±1.4 V)]. Input Noise (50 or 60 Hz Filtering): 510 nV rms Gain Error (50 or 60 Hz Filtering): 0.004% FSR Offset Error (50 or 60 Hz Filtering): 3 µV Measurement Sensitivity (Smallest Change in Temperature That Can Be Detected): Thermocouple Type J, K, T, E, N: 0.05°C Thermocouple Type R, S: 0.10°C Thermocouple Type B: 0.15°C Warm-Up Time: 20 minutes min Open Thermocouple Detect Response Time: 1 s CJC Sensor Accuracy (0 to 45°C): ±0.20°C typ, ±0.40°C max Channel Configuration Thermocouple (J, K, T, E, R, S, B, N): 32 differential channels Channel configuration is stored on EEPROM external to the isolated microcontroller by the firmware whenever any item is modified. Modification is performed by commands issued from an external application, and the configuration is made nonvolatile through the use of the EEPROM.
Digital Input Number of Inputs: 8 channels (16 when OMB-DAQ-TC-RACK connected to OMB-DAQ-TC-RACK-EXP32) Configuration: Fixed input Input Voltage Range: 0 to 15V Input Type: CMOS (Schmitt trigger) Input Characteristics: 100 k? pull-up resistor, 28.7 k? series resistor Maximum Input Voltage Range: 0 to 20V max (power on/off, relative to IGND pins) Pull-Up Configuration: All pins pulled up to 5V via individual 100 k? resistors using slide switch SW5; SW5 default position are on (pulled up) Transfer Rate (Software Paced): 500 port reads per second typ Input High Voltage: 1.3V min, 2.2V max Input Low Voltage: 1.5V max, 0.6V min Schmitt Trigger Hysteresis: 0.4V min, 1.2V max
Digital Output Number of Outputs: 32 channels, shared with alarms (64 when OMB-DAQ-TC-RACK connected to OMB-DAQ-TC-RACK-EXP32) Configuration: Open drain output Output Characteristics: 100 k? pull-up, open drain (DMOS transistor) Pull-Up Configuration: All pins pulled up to 5V through individual 100 k? resistors using slide switches SW1-SW4; the default positions for SW1-SW4 are on (pulled up) Transfer Rate (Software Paced): Digital output–500 port writes per second typ Output Voltage Range: 0 to 5V: Internal 100 k? pull-up resistors connected to 5V by default 0 to 15V: Max (using external pull-up resistor) Ground: Pins labeled IGND are isolated from AGND and chassis ground Off State Leakage Current: 0.1 µA Sink Current Capability: 100 mA max (continuous) per output pin DMOS Transistor On-Resistance (Drain to Source): 4 O
Environmental Operating Temperature Range: 0 to 45°C (32 to 113°F) Storage Temperature Range: -40 to 85°C (-40 to 185°F) Humidity: 0 to 90% RH non-condensing Mechanical Dimensions: 482.6 L x 128.6 W x 43.18 mm H (19 x 6.15 x 1.74") Weight: OMB-DAQ-TC-RACK: 3.8 lb (1.73 kg); OMB-DAQ-TC-RACK-EXP32: 3.2 lb (1.45 kg)
Will this interface to a SCADA system over Ethernet I/P such as Ignition (Inductive Automation) for data acquisition?
Asked by: GDG1
It will not interface to a SCADA system. You will need to use our universal library which is included in the software CD to communicate with the OMB-DAQ-TC-RACK.
Answered by: JA Engineer
Date published: 2019-08-28
How well do the OMB-DAQ-TC-RACK devices interface with a PLC? What is the minimum time to read in all 32 channels? I know I can expand to 64 channels but how about +/- 300 channels. Would 300 channels require (5) 64 channel setups?
Asked by: AlanAtTrane
Thanks for connecting with Omega. This unit is not designed to interface with a PLC. The max sample rate is 3 hz per channel. There is no provision for more than 64 inputs so you would need multiple setups and multiple computers running the software to do anything more than 64 channels. Please contact our Tech Support if you need further assistance finding a product to fit your application needs.
Answered by: Jane
Date published: 2019-05-22
Can you purchase the item calibrated to NIST?
Asked by: Rusty
OMB-DAQ-TC-RACK is calibrated with NIST traceable equipment, but at this moment calibration cert is only included when requested at the time of purchase. After discussing with the product manager we decided to include the cert on all future batches at no additional cost. Please email us at email@example.com if you have any further questions.