Data Translation DT3010 Series, Руководство по началу работы

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Chapter 5
64
Connecting Analog Input Signals
The DT740, STP268, and STP268-EC screw terminal panels support
both voltage and current loop inputs. You can connect analog input
voltage signals to the screw terminal panels in the following
configurations:
• Single-ended
−
Choose this configuration when you want to
measure high-level signals, noise is not significant, the source of
the input is close to the screw terminal panel, and all the input
signals are referred to the same common ground. When you
choose the single-ended configuration, all 32 analog input
channels are available.
• Pseudo-Differential
−
Choose this configuration when noise or
common-mode voltage (the difference between the ground
potentials of the signal source and the ground of the screw
terminal panel or between the grounds of other signals) exists
and the differential configuration is not suitable for your
application. This option provides less noise rejection than the
differential configuration; however, all 32 analog input channels
are available.
• Differential
−
Choose this configuration when you want to
measure low-level signals (less than 1 V), you are using an A/D
converter with high resolution (greater than 12 bits), noise is a
significant part of the signal, or common-mode voltage exists.
When you choose the differential configuration, 16 analog input
channels are available.
Note:
It is recommended that you connect all unused analog input
channels to analog ground.
This section describes how to connect single-ended,
pseudo-differential, and differential voltage inputs, as well as current
loop inputs to the screw terminal panels.