Contec ADI12-8(USB)GY, User Manual

Page: 31 / 69

3. Setup
24
ADI12-8(USB)GY
Sampling Rate
A/D Conversion Timing
The conversion time of Analog-Digital converter in ADI12-8(USB)GY is 10
µ
sec, and
total time indicates 'number of channels x 10
µ
sec + 20
µ
sec' until converting from
each analog signals to digital data. The time difference between 0 channel and 1
channel or later is 10
µ
sec
Sampling process time with internal CPU
ADI12-8(USB)GY samples analog signals with CPU which is inside of module.
The practicable minimum sampling period is about 600
µ
sec at single channel mode
through 2msec at multi-channel mode up to 32 channels, which is depends on the
sampling processing time inside a module. If the set of sampling clock time is shorter
than internal sampling processing time, sampling error will occur. Please refer to
explanation of AioSetAiSamplingClock in online-help of an API function library.
Converting channel 0 - channel 2
256K-word memory
A/D conversion data what internal CPU process with cycle of sampling clock is able
to store up to 256k-word to internal memory. The stored data is transferred in block
to host computer via USB. The share of memory is available, and the memory size
per channel is up to 32k-word at multi-channel mode with 8 channels. It is able to be
A/D sampling over 256k-word if transferring A/D conversion data to host computer
before the memory is full.
Even if the ADI12-8(FIT)GY is used, the size of memory used for storing the
conversion data has no change.
CAUTION
Sampling clock
Under sampling processing
Under sampling processing
1ch 2ch
(30
µ
sec) (10
µ
sec) (10
µ
sec)
1ch 2ch
(30 µ sec) (10 µ sec) (10 µ sec)
0ch 0ch
256K DATA memory
0ch 1ch 2ch 0ch 1ch 2ch
Remaining memories Data being transmitted to the host.
2ch