Contec ADI12-8(USB)GY, User Manual

Page: 28 / 69

3. Setup
ADI12-8(USB)GY
21
Measuring voltage
The following is an example of connection that connects to a reference voltage
generator by using a flat cable. When measuring devices only with plus and minus,
such as dry cell, because of 2-points connection, you should connect both CH0[-] and
AG to minus. The unused channel inputs must be connected to the analog ground.
Moreover, you should connect the module by using a 2-core shielded cable in
situations where the signal source is at a considerable distance from the module or
the noise immunity must be increased.
- When an analog ground is not connected, the conversion data can be
unpredictable.
- In situations where the connecting cable is subject to noise, accurate analog input
can fail to occur. To avoid this problem, the connecting cable should be installed
away from any sources of noise.
- An excessively long connecting cable can fail to ensure accurate analog input. The
connecting cable should be as short as possible.
- The analog signals that are input into the [+] input or [-] input should not exceed
the maximum input voltage relative to the module analog ground. A voltage
greater than the input voltage can damage the equipment.
- If either the [+] or [-] input pin is not connected, the resulting conversion data can
be unpredictable. If a channel is not connected to a signal source, both its [+]
input and [-] input pins must be connected to the analog ground.
CAUTION