Measurement Computing CIO-DAS1401/12 - Manual (Page 10)

CIO-DAS1401/12User's Guide Installing the CIO-DAS1401/12
10
5 4 WAIT EN 6 9 8 7
SW
A9
A8
A7
A6
A5
A4
A3 HEX
200
100
80
40
20
10
WAIT EN
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).
Note : Wait State Enable is typically not required. Leave the WAIT EN switch in the UP position (not enabled).
Disregard the numbers printed on the switch
When setting the base address, refer to the numbers printed in white on the printed circuit board.
DMA level
Use the DMA level switch (S7) to select a level of 1 or 3. The default setting is level 1 (see Figure 2). There are
other boards that use DMA levels, such as some network boards and IEEE-488 interface boards. Check to see if
you have other boards in your computer that use DMA channels 1 or 3.
3 1
Figure 2. DMA level switch
1/10 Clock frequency
Use the clock frequency XTAL jumper to select the frequency of the square wave used as a clock by the A/D
pacer circuitry. You can select either 1 MHz or 10 MHz. The pacer circuitry controls the sample timing of the
A/D. The output driving the A/D converter is also available at the CTR2 Out pin on the main connector.
To maintain full compatibility with the original DAS-16, the CIO-DAS1401/12 required a 1 MHz crystal
oscillator. When MetraByte redesigned the DAS-16 and added the faster 10 MHz crystal, a jumper was
provided to maintain compatibility with older software. The CIO-DAS1401/12 has the jumper because the
DAS-16 has the jumper. For older software, the jumper must be in the 1 MHz position. If you are not
concerned with compatibility with older software, use the 10 MHz position.
The CIO-DAS1401/12 is shipped with the jumper in the 1 MHz position (see Figure 3).
CL
KS
EL
10
1
Figure 3. Clock frequency jumper