Measurement Computing CIO-DAS801 - Manual (Page 10)

CIO-DAS801 User's Guide Installing the CIO-DAS801
10
5 4 3 6 9 8 7
SW
A9
A8
A7
A6
A5
A4
A3 HEX
200
100
80
40
20
10
08
Figure 1. Base address switches
In the default configuration shown in Figure 1, addresses 9 and 8 are DOWN, and all others are UP.
Address 9 = 200 hex (512 decimal) and address 8 = 100 hex (256 decimal); when added together they equal
300 hex (768 decimal).
Disregard the numbers printed on the switch
When setting the base address, refer to the numbers printed in white on the printed circuit board.
PC I/O addresses
Hex Range Function Hex Range Function
000-00F 8237 DMA #1 2C0-2CF EGA
020-021 8259 PIC#1 2D0-2DF EGA
040-043 8253 Timer 2E0-2E7 GPIB (AT)
060-063 8255 PPI (XT) 2E8-2EF Serial Port
060-064 8742 Controller (AT) 2F8-2FF Serial Port
070-071 CMOS RAM & NMI mask (AT) 300-30F Prototype card
080-08F DMA page registers 310-31F Prototype card
0A0-0A1 8259 PIC #2 (AT) 320-32F Hard disk (XT)
0A0-0AF NMI mask (XT) 378-37F Parallel printer
0C0-0DF 8237 #2 (AT) 380-38F SDLC
0F0-0FF 80287 numeric CO-P (AT) 3A0-3AF SDLC
1F0-1FF Hard disk (AT) 3B0-3BB MDA
200-20F Game control 3BC-3BB Parallel printer
210-21F Expansion unit (XT) 3C0-3CF EGA
238-23B Bus mouse 3D0-3DF CGA
23C-23F ALT bus mouse 3E8-3EF Serial port
270-27F Parallel printer 3F0-3F7 Floppy disk
2B0-2BF EGA 3F8-3FF Serial port
Input configuration
You can configure each analog channel for differential or single-ended input. You can set the input of each
channel using the bank of switches labeled
S2 (0 through 7) on the board. These switches correspond to
channels 0 to 7 of the analog inputs.
The switches are set by default for differential input. Differential inputs are 3-wire analog hookups consisting
of a signal high, signal low and chassis ground. The benefits of differential inputs are the ability to reject noise
which affects both signal high and low, and the ability to compensate for ground loops or potentials between
signal low and chassis ground.
Although differential inputs are often preferable to single ended inputs, the floating nature of a differential
input can make getting an accurate reading difficult. In those cases, the CIO-DAS801 inputs can be converted
to single-ended or modified differential.