Measurement Computing CIO-DAS08-AOH - Manual (Page 7)

3.2 INTERRUPT LEVEL SELECT
The interrupt jumper need only be set if the software you are using
requires it. If you do set the interrupt jumper, please check your PC's
current configuration for interrupt conflicts, and do not use IR2 in
PC/AT class machines (or higher).
There is a jumper block on the CIO-DAS08-AOx located just above the
PC bus interface (gold pins). The factory default setting is that no
interrupt level is set. The jumper is in the 'X' position.
Figure 3-2. Interrupt Jumper Block
If you need to pace conversions through hardware (either the on - board pacer or an external clock), move this jumper to one
of the other positions (see table 3-2).
The following table shows some typical interrupt assignments on a PC. The CIO-DAS08-AOx may be configured for
interrupt levels 2 through 7. The levels most often available are 5 and 7.
Table 3-2. Interrupt Assignments
Note: IRQ8-15 are AT only LPT IRQ7
UNASSIGNED IRQ15 FLOPPY DISK IRQ6
HARD DISK IRQ14 HARD DISK (XT)
LPT (AT) IRQ5
80287 NUMERIC CO-P IRQ13 COM OR SDLC IRQ4
UNASSIGNED IRQ12 COM OR SDLC IRQ3
UNASSIGNED IRQ11 RESERVED (XT)
INT 8-15 (AT) IRQ2
UNASSIGNED IRQ10 KEYBOARD IRQ1
RE-DIRECTED TO IRQ2
(AT) IRQ9 TIMER IRQ0
REAL TIME CLOCK (AT) IRQ8 PARITY NMI
DESCRIPTION NAME DESCRIPTION NAME
3.3 XTAL/PC BUS CLOCK JUMPER
The A/D pacer clock sources for the MetraByte DAS-8PGA and DAS-8 are different. The source for the DAS-8PGA is fixed
at 1 MHz while the source for the DAS-8 is dependent on PC bus speed. The CIO-DAS08-AOx attempts to deal with these
differences in a way that satisfies software written for either board.
The CIO-DAS08-AOx is equipped with a jumper which allows you to
choose the source of the A/D pacer clock pulse (Figure 3-3). The default
for this jumper is the 1 MHz position.
The MetraByte DAS-8PGA is only available with a 1MHz XTAL as the
source for the A/D pacer clock. This created problems for users who
wanted to use the DAS-8PGA in place of the DAS-8and use existing
software because the DAS-8 gets its A/D pacer clock pulse from the PC
Bus Clock.
Figure 3-3. Clock Source Jumper
If you need compatibility with the DAS-8 pacing scheme, you can select the PC Bus Clock as the source for the A/D pacer
clock.
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