Impulse 3088 - Manual (Page 7)

Card Setup
Sealevel Systems DUOCOM: Page 4
Interrupt Modes
Header E3 selects the interrupt mode for each port. Each port must be set in the
correct mode to insure proper installation.
‘N’ indicates the (N)ormal, single interrupt per port mode. ‘S’ Indicates the
(S)hared interrupt mode, which allows more than one port to access a single
IRQ. 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 E1. Consult your
particular software for IRQ selection. If no interrupt is desired, remove the
jumper. ‘R’ indicates the inclusion of a 1K ohm pull-down resistor required on
one port when sharing interrupts.
1
2
E3
N S R
Figure 3 - Header E3, Normal IRQ Mode
Set the jumpers to ‘S’ for shared interrupt mode on all blocks sharing an IRQ.
Also set one block for ‘R’. This provides the pull-down resistor circuit that
makes sharing of IRQs possible. If you are using more than one DUOCOM: or a
compatible adapter in a bus you should only have one port set to ‘R’. The
following example shows both ports sharing a single IRQ.
E3
N S R
1
2
Figure 4 - Header E3, Shared IRQ Mode