Owner's manual

OM-USB-TEMP User's Guide Sensor Connections
12
OM-USB-TEMP screw terminal descriptions
Pin Signal
Name
Pin Description Pin Signal
Name
Pin Description
1 I1+ CH0/CH1 current excitation source 27 I4- CH6/CH7 current excitation return
2 NC Not connected 28 GND Ground
3 C0H CH0 sensor input (+) 29 C7L CH7 sensor input (-)
4 C0L CH0 sensor input (-) 30 C7H CH7 sensor input (+)
5 4W01 CH0/CH1 4-wire, 2 sensor common 31 IC67 CH6/CH7 2 sensor common
6 IC01 CH0/CH1 2-sensor common 32 4W67 CH6/CH7 4-wire, 2 sensor common
7 C1H CH1 sensor input (+) 33 C6L CH6 sensor input (-)
8 C1L CH1 sensor input (-) 34 C6H CH6 sensor input (+)
9 GND Ground 35 NC Not connected
10 I1- CH0/CH1 current excitation return 36 I4+ CH6/CH7 current excitation source
CJC sensor CJC sensor
11 I2+ CH2/CH3 current excitation source 37 I3- CH4/CH5 current excitation return
12 NC Not connected 38 GND Ground
13 C2H CH2 sensor input (+) 39 C5L CH5 sensor input (-)
14 C2L CH2 sensor input (-) 40 C5H CH5 sensor input (+)
15 4W23 CH2/CH3 4-wire, 2 sensor common 41 IC45 CH4/CH5 2 sensor common
16 IC23 CH2/CH3 2 sensor common 42 4W45 CH4/CH5 4-wire, 2 sensor common
17 C3H CH3 sensor input (+) 43 C4L CH4 sensor input (-)
18 C3L CH3 sensor input (-) 44 C4H CH4 sensor input (+)
19 GND Ground 45 NC Not connected
20 I2- CH2/CH3 current excitation return 46 I3+ CH4/CH5 current excitation source
21 +5V +5V output 47 +5V +5V output
22 GND Ground 48 GND Ground
23 DIO0 Digital Input/Output 49 DIO7 Digital Input/Output
24 DIO1 Digital Input/Output 50 DIO6 Digital Input/Output
25 DIO2 Digital Input/Output 51 DIO5 Digital Input/Output
26 DIO3 Digital Input/Output 52 DIO4 Digital Input/Output
Use 16 AWG to 30 AWG wire for your signal connections.
Tighten screw terminal connections
When making connections to the screw terminals, be sure to tighten the screw until tight. Simply touching the
top of the screw terminal is not sufficient to make a proper connection.
Sensor input terminals (C0H/C0L to C7H/C7L)
You can connect up to eight temperature sensors to the differential sensor inputs (C0H/C0L to C7H/C7L).
Supported sensor categories include thermocouples, RTDs, thermistors, or semiconductor sensors.
Do not mix sensor categories within channel pairs. You can mix thermocouple types (J, K, R, S, T, N, E, and B)
within channel pairs, however.
Do not connect two different sensor categories to the same channel pair
The OM-USB-TEMP provides a 24 bit A/D converter for each channel pair. Each channel pair can monitor one
sensor category. To monitor a sensor from a different category, connect the sensor to a different channel pair
(input terminals).
Current excitation output terminals (±I1 to ±I4)
The OM-USB-TEMP has four dedicated pairs of current excitation output terminals (±I1 to ±I4). These terminals
have a built-in precision current source to provide excitation for the resistive sensors used for RTD and
thermistor measurements.
Each current excitation terminal is dedicated to one pair of sensor input channels:
I1+ is the current excitation source for channel 0 and channel 1
I2+ is the current excitation source for channel 2 and channel 3
I3+ is the current excitation source for channel 4 and channel 5
I4+ is the current excitation source for channel 6 and channel 7