Pepper Computer Modular Computers RS232 User Manual

Page of 320
SMART I/O User’s Manual
©1996 PEP Modular Computers GmbH
March 12, 1996
Page 5 - 19
5
Chapter 5  Analog Modules
5.1.8.4 SMDAD1GetVRaw
Syntax
error_code SMDAD1GetVRaw(u_int8 PortNr, u_int8
    Channel, int16 *pValue);
Description
This function fetches the  conversion result of a selected channel without
performing a gain or offset correction. The result is always a signed integer
value. If bipolar mode is selected, the function returns the 2’s complement
value of the original read.
Input
u_int8 PortNr
SM-Port to be accessed
u_int8 Channel
Number of the ADC input channel to access
(0-3)
int16 *pValue
Pointer to the location where the conversion
result will be stored
Output
error_code
SUCCESS
E_SEEK
if module was not initialized
E-BMODE
if the module is unknown
or standard OS-9 error code (refer to the OS-9
Technical Manual Error Codes Section).
Example
RetVal = SMDAD1GetVRaw(0, 2, 0x07FF);
Value (16-bit HEX)
Unipolar
Bipolar
Positive Full-Scale
$07FF
Positive Full-Scale
$07FF
+1LSB
$0001
+1LSB
$0001
0
$0000
-1LSB
$FFFF
  
Negative 
Full-Scale
$F800