HP NuDAQ I-9111DG/HR manual A/D Channel Control Register, Bit

Address: BASE + 0h

Attribute: read only

Data Format:

for 12-bits PCI-9111DG

Bit	7	6	5	4	3	2	1	0
BASE+0h	AD3	AD2	AD1	AD0	CH3	CH2	CH1	CH0
BASE+1h	AD11	AD10	AD9	AD8	AD7	AD6	AD5	AD4
for 16-bits PCI-9111HR
Bit	7	6	5	4	3	2	1	0
BASE+0h	AD7	AD6	AD5	AD4	AD3	AD2	AD1	AD0
BASE+1h	AD15	AD14	AD13	AD12	AD11	AD10	AD9	AD8

AD15 ~ AD0: Analog to digital data. AD11 is the Most Significant Bit (MSB) of PCI-9111DG while AD15 is the MSB of

PCI-9111HR. AD0 is the Least Significant Bit (LSB).

CH3 ~ CH0: A/D channel number from which the data is derived.

3.4A/D Channel Control Register

The PCI-9111 provides 16 single-ended analog input channel. The channel control register is used to set the A/D channels to be converted. Under non-auto scanning mode, the register sets the channel number for conversion. Under auto -scanning mode, the register sets the ending channel number.

Address: BASE + 6h

Attribute: write only

Data Format:

Bit	7	6	5	4	3	2	1	0
BASE+6h	CN7	CN6	CN5	CN4	CN3	CN2	CN1	CN0
BASE+7h	--	--	--	--	--	--	--	--

Where:

CNn: Multiplexer channel number.

CN7 is MSB, and CN0 is LSB.

There are 8 bits in this register. The 4 LSBs (CN0~CN3) are used to select on-board multiplexer. Usually, only the 4 LSBs are used and 16 input channels can be selected. However, if there is an extension board which can provide extension ability to 256 analog input channels, the 4 MSBs (CN4~CN7) can also be used to control the extension board.

Registers Format ∙ 15