Contec ADI16-4(USB) User Manual

3. Setup
ADI16-4(USB)
25
Sampling Rate
A/D Conversion Timing
The conversion time for the A/D converter in the ADI16-4(USB) is 10
µ
sec for voltage measurement
and 40
µ
sec for current measurement, and the total time required to convert each analog input signal to
digital data is (number of channels) x 10
µ
sec + 20
µ
sec for voltage input and (number of channels) x
40
µ
sec + 20
µ
sec for current input. There is a delay of 10
µ
sec per channel for voltage input and 40
µ
sec
per channel for current input between the conversion data for ch0 and the conversion data for ch1 and
subsequent channels.
Sampling process time with internal CPU
ADI16-4(USB) samples analog signals with CPU which is inside of module.
The practicable minimum sampling period is about 200
µ
sec at single channel mode through 1msec at
multi-channel mode up to 16 channels, which is depends on the sampling processing time inside a
module.
Measured values: The periods may be longer due to factors such as the load on the USB link.
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 64k-word at multi-channel mode
with 4 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 ADI16-4(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
(30µsec) (10µsec) (10µsec)
1ch 2ch
(30µsec) (10µsec) (10µsec)
0ch 0ch
2ch1ch
0ch 1
ch0ch 2ch
2ch
Data being transmitted to the host
256K data memories
Remaining memories
2ch1ch0ch
1ch0ch
2ch2ch1ch0ch 1ch
0ch 2ch
2ch2ch
Data being transmitted to the host
256K data memories
Remaining memories

Contec ADI16-4(USB) Specifications

General

Brand	Contec
Model	ADI16-4(USB)
Category	I/O Systems
Language	English