Omega 1002 User Manual
Page 39
Before performing A/D conversions, the JP1 jumper should be set for single-ended or
differential.
The software driver supports both polling and interrupt driven A/D, however, polling
is the simplest way to perform an A/D conversion.
The settling time of multiplexer depends on the impedance of the signal source.
Because the driver does not incorporate the settling time, the user needs to program a
delay when switching from one channel to another or when changing gains.
Suggested Settling Times
One settling time is suggested for all ranges of the OME-PCI-1002L. The settling time
for the OME-PCI-1002H is based on the analog input range. The table below shows the
suggested settling times for each range.
OME-PCI-1002L Settling Time: 33
µseconds for all ranges
OME-PCI-1002H Settling Time
Input Range
Settling Time
± 10V
23
µS
± 5V
28
µS
± 0.1V
140
µS
± 0.01V
1300
µS
The software driver provides a machine independent timer, P1002_Delay(), for
settling time delay. If the user calls P1002_Delay(), counter 0 will be reserved and can
not be used as a user programmable timer/counter.
The A/D converter requires a trigger signal to start an A/D conversion cycle. The
OME-PCI-1002 supports three trigger modes, software, pacer and external trigger.
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