iDAQ-731_751_763D User Manual
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2.2.3
TTL Digital Input
A digital input/output (DI/O) channel can be configured by software to perform digital
input measurement, which is the power-on default configuration, or digital output
generation. When performing digital input measurement, the voltage logic level
between the digital input (DI) terminal and the digital ground (DGND) terminal is mea
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sured. To prevent undetermined or fluctuating results when input is floating, the digi
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tal input channel is internally pulled-down. This is shown in Figure 2.6.
Figure 2.6 Digital input signal connection.
The input voltage must be either higher than the minimum value of ON state or lower
than the maximum value of OFF state for deterministic result. If the input voltage is
between these two values, the result is undetermined, which may be ON or OFF. In
addition, do not input a voltage higher than the maximum allowable value of ON state
or lower than the minimum allowable value of OFF state. The device may be dam
-
aged under such circumstance. Refer to the device specifications for ON and OFF
state voltage ranges.
The digital input channel can also sense the status of an external switch. The status
of an external switch which is connected between the external source and the DI ter
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minal is sensed as shown in Figure 2.7. Be sure the voltage of the external source is
within the allowable range of ON state as specified in the device specifications.
Summary of Contents for iDAQ-731
Page 1: ...User Manual iDAQ 731 iDAQ 751 iDAQ 763D Digital I O and Relay Industrial DAQ Modules ...
Page 8: ...iDAQ 731_751_763D User Manual viii ...
Page 11: ...Chapter 1 1 Start Using IDAQ 731 751 763D ...
Page 16: ...iDAQ 731_751_763D User Manual 6 ...
Page 17: ...Chapter 2 2 Installation and Field Application ...
Page 28: ...iDAQ 731_751_763D User Manual 18 ...
Page 29: ...Chapter 3 3 Function Details ...
Page 42: ...iDAQ 731_751_763D User Manual 32 Figure 3 27 Streaming generation with retrigger ...
Page 44: ...iDAQ 731_751_763D User Manual 34 ...
Page 45: ...Appendix A A Specifications ...
Page 50: ...iDAQ 731_751_763D User Manual 40 ...
Page 51: ...Appendix B B System Dimensions ...
Page 52: ...iDAQ 731_751_763D User Manual 42 B 1 iDAQ Modules ...
Page 53: ...43 iDAQ 731_751_763D User Manual Appendix B System Dimensions ...