OMB-DAQ-2408 Series User's Guide
Functional Details
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Figure 4. DIFF mode pin out
* These pins are labeled "NC" (no connection) on the OMB-DAQ-2408.
Signal connections
Input isolation
OMB-DAQ-2408 Series devices are isolated data acquisition devices. The analog I/O, digital I/O, counters, and
all the digital control/timing are referenced to an isolated ground as shown in the figure below. This ground is
physically and electrically separate from the ground used by the circuit connected to the system bus interface.
Isolation provides a barrier between the host computer and potentially hazardous voltages by physically and
electrically separating two parts of the measurement device.
The "non-isolated" ground is common to the chassis ground of the computer, while the "isolated" ground is
not.
All analog measurements are made relative to the isolated ground. See Figure 5 for details.
