i240 and i4xx MAXIMUM SAMPLE RATES REFERENCE > ADVANCED TECHNIQUES >
The following table shows maximum aggregate sample rates for
an i240 USB controller attached to an
i4xx Card Cage. To calculate the sample rate for each
channel, divide by the number of channels attached to the i240 controller. For example,
if the maximum aggregate sample rate is 166Ksamples/sec/controller, and you digitize 4 channels,
then you could digitize each channel at 41Ks/sec/channel. Or, digitize two channels at 88K each.
One can attach up to eight i240/i60x controllers to a computer to increase total system throughput. For example,
four i240 controllers (where each is attached to a separate i4xx Card Cage or i100 box) can digitize 16 total channels
at 41Ks/sec/channel; or 32 channels at 20.5K each. In this example, each controller runs at 166Ks/sec/controller
and the entire system runs at 664Ks/sec/system.
For more details on working with multiple
controllers, click here.
The last column of the below table refers to low level signals (≤ ±80mV range). These are common when working with sensors such as a
strain gage, load cell or thermocouple. Notice that the only way to digitize
fast (e.g. ≥ 2K s/sec/controller) with a low level signal is to digitize directly into an i423 card
(to get ≤ 68K s/sec/controller).
Max Aggregate Sample Rate per Controller (K samples/second/controller)