Black Box IC171C manual Option Selection, Header E1 Factory Default. IRQ 4 Selected

RS422/485 SERIAL INTERFACE PLUS

4. Option Selection

NOTE

Be sure to set the address selections and jumper options before installation.

The RS422/485 Serial Interface Plus contains several jumpers that must be set for proper operation.

E1: This header selects the interrupt request for the RS422/485 Serial

Interface Plus. If COM1: is selected, this jumper must be on the IRQ4 setting.

If COM2: is selected, this jumper must be on IRQ3. 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.

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. Windows 3.1, OS/2, and UNIX® applications typically require a separate IRQ setting for each address. Check your software configuration instructions to determine the most appropriate.

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Figure 4-1. Header E1 (Factory Default). IRQ 4 Selected.

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