Pepper Computer Modular Computers RS485 - Manual (Page 176)

SMART I/O User’s Manual
March 12, 1996 ©1996 PEP Modular Computers GmbH Page 5 - 20
Chapter 5 Analog Modules
5.1.8.5 SMDAD1GetV
Syntax
error_code SMDAD1GetV(u_int8 PortNr, u_int8 Channel,
int16 *pValue);
Description
This function fetches the conversion result of a selected channel. A gain and
offset correction is done with the use of the selected conversion table. 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 = SMDAD1GetV(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