5.4.1 A/D Conversion Trigger Modes
The PCI-1002 series supports three trigger modes.
1 : Software Trigger :
Write any value to the A/D software trigger control register, BASE+1Ch, and
it will initiate an A/D conversion cycle. This mode is very simple but
controlling the sampling rate very difficult.
2 : Pacer Trigger Mode :
See section 4.2 for a block diagram for this pacer timer. The sample rate of
pacer is very precise.
3 : External Trigger Mode :
When a rising edge of external trigger signal is applied, an A/D conversion
will be performed. The external trigger source comes from Pin-19 of CON3.
5.4.2 A/D Transfer Modes
PCI-1002 series supports two transfer modes.
1 : Polling transfer :
This mode can be used with all trigger modes. You have to
disable timer 0
before polling. The software reads the A/D data register from [BASE+30h]
when READY bit of Register [BASE +10h] =1.
2 : Interrupt transfer:
This mode can be used with either a pacer trigger or external. A hardware
interrupt signal is sent to the PC when an A/D conversion is completed.
If using interrupt transfer, it is recommended to use PCI-1002 software
driver.
PCI-1002 Series User Manual (Ver.2.8, Oct. 2011, PMH-015-28)
45
