Contec AI-1608GY-USB User Manual page 49

6. Functions
Start Condition
The condition for controlling the start of sampling can be selected from among software, input data
comparison, an external trigger. The conditions for controlling the start and stop of sampling are
completely independent of each other; they can be set separately.
- Software
The product starts sampling and storing input data to memory immediately after the operation start
command is issued.
- Input data comparison
When the operation start command is issued, the product compares the analog signal input through
a specified channel to the value of the preset comparison level. If the analog signal satisfies the
condition, the product starts storing input data.
Level comparison conditions are set as two conditions: level and direction.
The above sketch shows that the level comparison condition is satisfied in the rising direction.
The start condition is satisfied when the analog signal at the specified channel passes the
comparison level in the rising direction. Input data items are stored to memory, starting with
those at solid dots.
The above sketch shows that the level comparison condition is satisfied in the falling direction.
The start condition is satisfied when the analog signal at the specified channel passes the
comparison level in the falling direction. Input data items are stored to memory, starting with
those at solid dots.
If you set the level comparison directions to both directions, the start condition is satisfied when
the analog signal passes the level both in the rising and falling directions.
With this product, the level comparison is performed by the device driver, so sampling is
performed internally before the level condition is satisfied. Therefore, due to the load state (such
as the conversion speed and the CPU), an overflow may cause the product to stop before the level
comparison condition is satisfied.
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AIO-160802GY-USB, AI-1608GY-USB