Omega OMB-DAQ-2416_4AO 사용자 설명서

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Placing a notch of the A/D digital filter at 60 Hz (setting A/D data rate = 60 S/s, 10 S/s, 5 S/s or 
2.5 S/s) further improves the common mode rejection of this frequency. 

When any item is changed, the firmware stores channel configurations in the EEPROM of the isolated 
microcontroller. An external application issues commands over the USB to make changes, and the configuration 
is made non-volatile through the use of the EEPROM. 

When connecting differential voltage inputs to a floating voltage source, provide a DC return path from each 
voltage input to ground. To do this, connect a resistor from each input to a GND pin (pins 18, 36, 39, 42, 44, 46, 
66, 81, 84). A value of approximately 100 kΩ can be used for most applications. 

Leave unused input channels either floating or tied to GND (pins 18, 36, 39, 42, 44, 46, 66, 81, 84). 

Source impedances should be kept as small as possible to avoid settling time and accuracy errors. 

For each voltage/thermocouple channel configured as differential, you essentially lose one single-ended 
channel. You can add channels by connecting to an OMB-AI-EXP32.  

Table 2. Channel configurations 

CxH/CxL 

Thermocouple 

16 differential channels  

CxH/CxL 

Voltage 

32 individually-configurable channels that can be configured as either single-ended or 
differential.  

CxH/CxL 

Voltage 

Table 3. Compatible sensor type specifications 

Thermocouple 

J: -210 °C to 1200 °C 

K: -270 °C to 1372 °C 

R: -50 °C to 1768 °C 

S: -50 °C to 1768 °C 

T: -270 °C to 400 °C 

N: -270 °C to 1300 °C 

E: -270 °C to 1000 °C 

B: 0 °C to 1820 °C 

Thermocouple measurement accuracy specifications include polynomial linearization error, cold-junction 
compensation measurement error, and system noise. These specs are for one year, or 3000 operating hours, 
whichever comes first.  

There is a CJC sensor for each terminal block of the module. The accuracy listed below assumes the screw 
terminals are at the same temperature as the CJC sensor.  

The accuracy errors shown do not include the inherent accuracy error of the thermocouple sensor itself. Contact 
your thermocouple supplier for details on the actual thermocouple sensor accuracy limitations.