OMB-DAQ-2408 Series User's Guide
Functional Details
17
Figure 9. OMB-DAQ-2408 Series data rate vs. resolution example
Analog output (OMB-DAQ-2408-2AO only)
The OMB-DAQ-2408-2AO has two 16-bit analog outputs (
AOUT0
and
AOUT1
). Both outputs can be updated
simultaneously at a rate of 500 S/s per channel. One output can be updated at a rate of 1000 S/s. The output
range is fixed at ±10 V. The outputs default to 0 V when the host computer is shut down or suspended, or when
a reset command is issued to the device.
Digital I/O
You can connect up to eight digital I/O lines to
DIO0
through
DIO7
. The digital I/O terminals can detect the
state of any TTL-level input.
Digital input voltage ranges of up to 0 to +15 V are permitted, with thresholds of 0.6 V (low) and 2.2 V (high).
Each DIO channel is an
open-drain
, which, when used as an output, is capable of sinking up to 150 mA for
direct drive applications.
Figure 10 shows an example of a typical DIO connection.
Figure 10. Digital output connection example
The figure represents connections for one channel. The other seven channels are connected in the same manner.
The maximum sink current is 150 mA per 8-channel bank, or if all eight channels are used, 18 mA (maximum)
per channel.
Internal pull-up/pull-down capability
Unconnected inputs are pulled low by default to 0 V through 47 kΩ resistors via jumper
J6
on the circuit board.
The pull-up/pull-down voltage is common to all 47 kΩ resistors. Complete the following steps to configure
these inputs to pull high (+5V).
