PCI-1002 Series Card
12-bit, 110 kS/s or 44 kS/s Multi-function Board
User Manual, Ver. 3.0, Jun. 2018, PMH-015-30, Page: 57
AD conversion flow:
Before using the AD converter, please select either single-ended or differential input (JP1).
The software driver supports two different modes:
polling and interrupt.
The user can control the
AD conversion by polling mode very easy. Using the software driver is recommended if using
interrupt.
The multiplexer can select 32 single-ended or 16 differential signals into the gain control module.
The settling time of multiplexer depends on the impedance of the signal source.
Because the
software
doesn’t control the settling time
,
please make sure to leave enough settling time if
switching from one channel to the next channel.
The gain control module also needs settling time if gain control code changed. Again, because the
software
doesn’t control settling time
,
please delay enough settling time if the gain control code is
changed.
Remember to delay the extra setting time when gain of channel is changed.
The software driver provides
a machine independent timer, P1002_Delay()
, for settling time delays.
This subroutine assumes a machine independent timer will be implemented. However, if using call
P1002_Delay(), the counter 0 will be reserved and can’t be used as a user programmable
timer/counter.
The gain control module’s output feeds into the AD converter.
The AD converter needs a trigger
signal to start an AD conversion cycle
. The PCI-1002 series supports three trigger modes:
software,
pacer, and external trigger
.