Impulse 3088 - Manual (Page 6)

Card Setup
Sealevel Systems DUOCOM: Page 3
IRQ Selection
Headers E1 and E2 select the interrupt request for each serial port (E1 - Port 1,
E2 - Port 2). If COM1: is selected, the corresponding jumper must be on the
IRQ4 setting. If COM2: is selected, the corresponding jumper must be on IRQ3.
Note: Most communications software applications default COM3: to IRQ4 and
COM4: to IRQ3. This requires the sharing of interrupts between COM1:
and COM3:, and between COM2: and COM4:. While this is the default, it
is not always the preferred setting. Check your software configuration
instructions to determine the most appropriate IRQ selection.
2/9 3 4 5 7 10 11 12 15
2/9 3 4 5 7 10 11 12 15
E2
E1
Figure 2 - Header E1 and E2, IRQ Selection
Any two or more ports can share a common IRQ by placing the jumpers on the
same IRQ setting, and setting the appropriate selections at E3. Consult your
particular software for IRQ selection. If no interrupt is desired, remove the
jumper.