Black Box IC113C Manual

A SERVICE OF

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8

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

Figure 4-1. 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 E9 and E10.

Consult your particular software for IRQ selection. If no interrupt is desired,

remove the jumper.

NOTE

IRQ 2 on AT class machines is not available. IRQ 9 is substituted in place

of IRQ 2. To select IRQ 9, place jumper in the IRQ 2 position.

Figure 4-2 shows Headers E9 and E10. “N” indicates the normal, single

interrupt per port mode. The “S” indicates the shared interrupt mode, which

allows more than one port to access a single IRQ. The “M” indicates that the

inclusion of a 1K-ohm pull-down resistor is required on one port when

sharing interrupts. E10 sets Port 1 and E9 sets Port 2.

E1

E2

2/9 3 4 5 7 10 11 12 15

2/9 3 4 5 7 10 11 12 15