PCI-1202/1602/180x Series Card
Multi-Function Boards
User Manual/ Ver. 4.8/ Mar. 2015/ PMH-0014-48/ Page: 80
6.5.3 The A/D Software Trigger Register
Writing to this port will perform a software trigger signal to trigger an A/D conversion. Although the
PC can send very fast trigger signal (more than 333 k ), the max. sampling rate of A/D conversion
cannot over 330 k Samples/Sec.. The timing diagram is given as follows:
Figure 6.5.3-1: Trigger delay time.
The sample code of software trigger A/D conversion is given as follows:
P180x_AdPollingHex(…) is designed for PCI-1800/1802 series
P1202_AdPollingHex(…) is designed for PEX-1202/PCI-1202 series
P1602_AdPollingHex(…) is designed for PCI-1602 series
WORD
P180X_AdPollingHex
(Word *AdVal)
{
WORD wVal, wTime;
//Clear FIFO
outport(wAddrCtrl,0x2000);
//B15=0=clear FIFO, B13=1=not MagicScan controller cmd
outport(wAddrCtrl,0xA000);
//B15=1=no clear FIFO, B13=1= not MagicScan controller cmd
outport((WORD)(wA4),0xffff);
/* generate a software trigger pulse */
wTime=0;
for (;;)
{
wVal=inport(wAddrCtrl)&0x20;
// wait for ready signal
if (wVal!=0) break;
/* If B4==1
A/D data ready */
wTime++;
if (wTime>32760) return(AdPollingTimeOut);
}
AdVal=inport(wAddrAdda)&0x0fff;
/*
Read the available A/D data from FIFO
*/
return(NoError);
/*
0xffff for PCI-1602/1602F
*/
}
A/D
Busy
Software
trigger
3
s
Delay time
Conversion Time
