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Installation
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AO-1604VIN-USB / AO-1604AIN-USB Reference Manual
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53
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5.
Connecting Digital I/O Signals
Digital I/O signals can be used as control I/O signals (external trigger input signals, sampling clock
input signals, etc.). The following section shows examples of how to connect signals.
1.
Input Circuit
The following is a digital I/O circuit of the interface (connector) part.
External digital signals given to signal input section are TTL level, and each signal is taken to a PC
using negative logic. Each signal input section is pulled-up in this product, therefore, outputs of relay
contacts or semiconductor switch can be connected directly between this signal input and signal
common.
*Input pins are indicated as DI xx. xx corresponds to input bits.
DI 00 - DI02 can be used as control signals listed below. However, when using them as control
signals, they cannot be used as general-purpose digital inputs.
DI 00: External Start Signal Input
DI 01: External Stop Signal Input
DI 02: External Clock Signal Input
Refer to “
Control Signal Timings(page84)
” for an operation timing when using signals as control
signals.
