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Chapter 3
Functional Details
Analog input acquisition modes
The BTH-1208LS can acquire analog input data in three different modes – software paced, continuous scan, and
burst scan.
Software paced mode
In software paced mode you can acquire one analog sample at a time. You initiate the A/D conversion by
calling a software command. The analog value is converted to digital and returned to the computer. You repeat
this procedure until you have the total number of samples that you want from one channel.
When communicating over a Bluetooth connection, the typical throughput sample rate in software paced
mode is 10 S/s (system-dependent).
When communicating over a USB connection, the typical throughput sample rate in software paced mode
is 250 S/s (system-dependent).
Continuous scan mode
In continuous scan mode you can acquire data from up to eight channels. The analog data is continuously
acquired and converted to digital values until you stop the scan.
When communicating over a Bluetooth connection, the maximum continuous scan rate of 1024 S/s is an
aggregate rate. The total acquisition rate for all channels cannot exceed 1024 S/s. The following table lists
the scan rates when scanning from one to eight channels in Bluetooth mode.
Maximum continuous scan rate in Bluetooth mode
# channels scanned
Scan rate (S/s)
1
1024
2
512
3
341.33
4
256
5
204.8
6
170.67
7
146.28
8
128
When communicating over a USB connection, the maximum continuous scan rate of 50 kS/s is an
aggregate rate. The total acquisition rate for all channels cannot exceed 50 kS/s. Data is transferred in
blocks of 32 samples from the device to the memory buffer on your computer.
The following table lists the scan rates when scanning from one to eight channels in USB mode.
Maximum continuous scan rate in USB mode
# channels scanned
Scan rate (kS/s)
1
50
2
25
3
16.70
4
12.50
5
10
6
8.30
7
7.14
8
6.25
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