Omega Engineering OME-A8111 manual Clear Interrupt Request, 6 A/D Gain Control Register

2.4.5Clear Interrupt Request

(WRITE)	Base+8: Clear Interrupt Request Format
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
X	X	X	X	X	X	X	X

X = don‘t care, XXXXXXXX = any 8 bit data is valid

If OME-A-8111 is working in the interrupt transfer mode, an on-board hardware status bit will be set after each A/D conversion. This bit must be cleared by the software before next hardware interrupt. Writing any value to address BASE+8 will clear this hardware bit and the hardware will generate another interrupt when next the A/D conversion is completed.

2.4.6A/D Gain Control Register

(WRITE)	Base+9: A/D Gain Control Register Format
Y	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
X	X	X	X	X	GAIN2	GAIN1	GAIN0

The OME-A-8111 provides a gain factor of 1/2/4/8/16. The gain controls register control

the gain of the A/D input signal. Bipolar/Unipolar will affect the gain factor.

NOTE : If the gain control code is changed, the hardware needs to have extra gain

settling time. The gain settling time is different for different gain control code. The

software driver does not monitor the gain settling time, so the user needs to delay the gain settling time if the gain changed.

OME-A-8111 GAIN CONTROL CODE TABLE

GAIN	Input Range	GAIN2	GAIN1	GAIN0	Settling Time
1	+/- 5V	0	0	0	2.1 µs
2	+/- 2.5V	0	0	1	2.5 µs
4	+/- 1.25V	0	1	0	2.7 µs
8	+/- 0.0625V	0	1	1	3.6 µs
16	+/- 0.03125V	1	0	0	4.1 µs

OME-A-8111 Hardware Manual (ver.1.1, Jul/2003) 14