Data Translation DT9871, Руководство пользователя

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Chapter 6
90
Thermocouple Input Channels
For channels that support thermocouples, you can attach a voltage input or any of the
following thermocouple types in a mix and match fashion: B, E, J, K, N, R, S, and/or T.
By default, these channels are configured for voltage inputs. You can specify the thermocouple
types for channels using the DT-Open Layers Control Panel applet, described on
page 40 , the
QuickDAQ application, or by using an API call in your application program.
Note: In a mix-and-match system, it is easy to accidentally mismatch the software and
hardware configuration for a channel. Therefore, it is recommended that you pay particular
attention when configuring channels, since the resultant errors may be not large enough to
notice initially, but may be significantly larger than the accuracy specification for the
instrument.
Since each channel has its own 24-bit A/D, analog inputs are measured simultaneously. Refer
to
page 96 for more information on specifying the channels for a scan.
Table 3 lists the supported measurement range for each thermocouple type. (Refer to page 92
for information on the supported input range for voltage measurements.)
VOLTpoint DT9873-8 8 8 voltage inputs (numbered 0 to 7)
DT9873-16 16 16 voltage inputs (numbered 0 to 15)
DT9873-24 24 24 voltage inputs (numbered 0 to 23)
DT9873-32 32 32 voltage inputs (numbered 0 to 31)
DT9873-40 40 40 voltage inputs (numbered 0 to 39)
DT9873-48 48 48 voltage inputs (numbered 0 to 47)
MEASURpoint DT9874-16T-16R-16V 48 16 thermocouple inputs (numbered 0 to 15)
16 RTD inputs (numbered 16 to 31)
16 voltage inputs (numbered 32 to 47)
Table 2: Number and Type of Analog Input Channels (cont.)
Instrument
Type Models
# of
Analog Input
Channels Channel Types