USB-TEMP User's Guide
Sensor Connections
3-2
Table 3-1. 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. It is permitted to 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 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 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.
