OM-WEB Series User's Guide
Functional Details
25
Data linearization
An on-board microcontroller automatically performs linearization on RTD and thermistor measurements.
RTD measurements are linearized using a Callendar-Van Dusen coefficients algorithm (you select DIN,
SAMA, or ITS-90).
Thermistor measurements are linearized using a Steinhart-Hart linearization algorithm (coefficients
provided by the sensor manufacturer's data sheet).
External components
OM-WEB Series hardware has the following external components, as shown in Figure 11.
Screw terminals
Ethernet port
External power connector
Status LEDs (POWER/COMM and LINK/ACTIVITY)
Digital output voltage switch
Factory default reset button
1
Screw terminal pins 1 to 26
4
Factory default reset button
7
Ethernet port
2
Screw terminal pins 27 to 52
5
POWER/COMM LED (top)
LINK/ACTIVITY LED (bottom)
3
Power connector
6
Digital output voltage switch
Figure 11. OM-WEB Series components
Screw terminals
The screw terminals provide connections for sensors, digital channels, power, and ground. Detailed information
is provided in Chapter 3,
, beginning on page 17.
Ethernet port
OM-WEB Series devices have one 10BASE-T communication port. The port connector is an eight-position
RJ-45 connector. Use the Ethernet cable provided to connect the device to a local or wide area network or to a
hub attached to a single computer. Use a CAT-5 (or higher) shielded or unshielded twisted pair crossover cable
to connect directly to a computer. The maximum communication distance without using a repeater is
100 meters. Data can transmit up to 100 meters at speeds of up to 100 Mbps using only one crossover Ethernet
cable connected to your computer.
External power connector
Use the supplied external power supply (Omega p/n OMB-DAQ-2416-ADAP) to power OM-WEB Series
hardware.