Omega Engineering OME-A8111 사용자 설명서

 
 
 

Then the user must decide which A/D conversion mode will be used. The software driver 

supports three different modes.  The user can control the A/D conversion by polling mode 
very easily (sec. 2.4.9). It is recommended to use the software driver if using interrupt or 
DMA mode.   

 
The analog input signals come from CN1.   
 
The multiplexer can accept 8 single-ended lines into the gain control module. The gain 

control module also needs settling time if the gain control code changed. Because the 
software doesn’t monitor the settling time, the user should reserve enough settling time 
if switching from one channel to the next (sec. 2.4.6).   

 
The output of the gain control module feeds into the A/D converter. The A/D converter 

needs a trigger signal to start an A/D conversion cycle. The OME-A-8111 supports 
software trigger or pacer trigger mode. 

 
 
 
 
 

 
OME-A-8111 supports two trigger modes. 
 
1 :  Software Trigger : 

Writes any value to the A/D software trigger control register, BASE+A, will initiate an 
A/D conversion cycle. This mode is very simple but very difficult to control the 
sampling rate. 
 

2 :  Pacer Trigger Mode : 

The block diagram of the pacer timer is shown in section 2.6. The pacer timer can give 
very precise sampling rates. 

OME-A-8111 Hardware Manual (ver.1.1, Jul/2003)                                      22