Digi RCM4000 - Manual (Page 57)

User’s Manual 51
Reads the value of an analog input channel using the Direct Mode method of addressing the A/D
converter. Note that it takes about 1 second to ensure an internal capacitor on the A/D converter is
charged when the function is called the first time.
PARAMETERS
channel is the channel number (0 to 7) corresponding to LN0_IN to LN7_IN
opmode is the mode of operation:
SINGLE —single-ended input
DIFF —differential input
mAMP —4–20 mA input
gaincode is the gain code of 0 to 7 (applies only to Prototyping Board):
RETURN VALUE
A value corresponding to the voltage on the analog input channel:
0–2047 for 11-bit A/D conversions (bit 12 for sign)
ADOVERFLOW (defined macro = -4096) if overflow or out of range
ADTIMEOUT (defined macro = -4095) if conversion is incomplete or busy-bit timeout
SEE ALSO
anaIn, anaInConfig, anaInDriver
unsigned int anaIn(unsigned int channel,
int opmode, int gaincode);
channel SINGLE DIFF mAMP
0 +AIN0 +AIN0 -AIN1 +AIN0
*
* Not accessible on Prototyping Board.
1 +AIN1 +AIN1 -AIN0* +AIN1*
2 +AIN2 +AIN2 -AIN3 +AIN2*
3 +AIN3 +AIN3 -AIN2* +AIN3
4 +AIN4 +AIN4 -AIN5 +AIN4
5 +AIN5 +AIN5 -AIN4* +AIN5
6 +AIN6 +AIN6 -AIN7* +AIN6
7 +AIN7 +AIN7 -AIN6* +AIN7*
Gain Code Multiplier
Voltage Range
(V)
0 Ч1 0–22.5
1 Ч2 0–11.25
2 Ч4 0–5.6
3 Ч5 0–4.5
4 Ч8 0–2.8
5 Ч10 0–2.25
6 Ч16 0–1.41
7 Ч20 0–1.126