Keithley KPCI-3110, Руководство пользователя

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KPCI-3110 and KPCI-3116 User’s Manual Functional Description 2-5
Figure 2-2
An example using dynamic digital outputs
As analog input channel 5 is read, 1 is output to dynamic digital output line 1, and 0 is output to
dynamic output line 0 (since 2 in binary format is 10). As analog input channel 6 is read, 0 is
output to both dynamic digital output lines. As analog input channel 7 is read, 0 is output to
dynamic digital output line 1, and 1 is output to dynamic output line 0 (since 1 in binary format
is 01). As analog input channel 8 is read, 1 is written to both dynamic digital output lines.
NOTE Expansion accessories use some of the dynamic digital output signals.
Therefore, you cannot use this feature and an expansion channel in the
same task.
Input ranges and gains
Each channel on the KPCI-3110 or KPCI-3116 board can measure unipolar and bipolar analog
input signals. A unipolar signal is always positive (0 to 10V on KPCI-3110 and KPCI-3116
boards), while a bipolar signal extends between the negative and positive peak values (±10V on
KPCI-3110 and KPCI-3116 boards).
Through DriverLINX software, specify the range as 0 to 10V for unipolar signals or
−
10V to
+10V for bipolar signals. Note that the range applies to the entire analog input subsystem, not to
a specific channel.
KPCI-3110 and KPCI-3116 boards also provide gains 1, 2, 4, and 8, which are programmable
per channel.
Table 2-1 lists the effective ranges supported by KPCI-3110 and KPCI-3116 boards
using these gains.
For each channel, choose the gain that has the smallest effective range that includes the signal
you want to measure. For example, if the range of your analog input signal is ±1.5V, specify a
range of
−
10V to +10V for the board and use a gain of 4 for the channel; the effective input
range for this channel is then ±2.5V, which provides the best sampling accuracy for that channel.
The way you specify gain depends on how you specified the channels, as described in the fol-
lowing subsections.
Table 2-1
Gains and effective ranges
Gain Unipolar Analog Input Range Bipolar Analog Input Range
1 0 to 10V ±10V
2 0 to 5V ±5V
4 0 to 2.5V ±2.5V
8 0 to 1.25V ±1.25V
Channel List
Dynamic Digital
Values
Dynamic Digital
Outputs
Line 1 Line 0
5
6
7
8
2
0
1
3
1
0
0
1
0
0
1
1