unsigned int anaIn(unsigned int channel, int opmode, int gaincode);

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

channel

SINGLE

DIFF

mAMP

 

 

 

 

0

+AIN0

+AIN0 -AIN1

+AIN0*

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*

 

 

 

 

* Not accessible on Prototyping Board.

gaincode is the gain code of 0 to 7 (applies only to Prototyping Board):

Gain Code

Multiplier

Voltage Range

(V)

 

 

0

×1

0–22.5

 

 

 

1

×2

0–11.25

 

 

 

2

×4

0–5.6

 

 

 

3

×5

0–4.5

 

 

 

4

×8

0–2.8

 

 

 

5

×10

0–2.25

 

 

 

6

×16

0–1.41

 

 

 

7

×20

0–1.126

 

 

 

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

User’s Manual

51

Page 57
Image 57
Digi RCM4000 user manual Single Diff, Gain Code Multiplier Voltage Range