National Instruments 1128 用户手册

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Chapter 2
Using the SCXI-1127/1128
© National Instruments Corporation
2-17
Software Scanning
Unlike hardware scanning, software scanning does not use 
hardware-generated triggers. In software scanning, a list of channels kept 
by the software is scanned by selecting the desired channel on the 
SCXI-1127/1128 and making the required measurement. Refer to the 
NI-SWITCH documentation for more information on software scanning.
Making Temperature Measurements
You can use the SCXI-1127/1128 to measure a variety of temperature 
devices including thermocouples, RTDs, and thermistors. The following 
sections discuss how to use these types of sensors with the 
SCXI-1127/1128.
Making Thermocouple Measurements
Figure 2-16 shows a thermocouple (V
1
) connected to channel 3 on the 
SCXI-1331 terminal block. The thermocouple is connected in the 2-wire 
configuration. Due to the small voltages that thermocouples produce, 
National Instruments recommends that you connect them in a 2-wire 
(differential) configuration versus a 1-wire configuration.