B&B Electronics 3PXCC2b, 3PXCC1A, 3PXCC1b, 3PXCC2a Address and IRQ Setting Address Switch Setup

Chapter 4: Address and IRQ Setting

Address Switch Setup

A Windows PC has I/O port addresses and memory addresses. Some devices use both types of addresses. I/O port addresses have a 64K address space. Devices may decode all 16 address bits or only some of the lower bits. Traditionally, serial cards have only decoded 10 bits of the address bus. Recently this has begun to cause address conflicts with full 16 bit decoded devices, most notably between video cards and COM 4. B&B has solved these conflicts by decoding all 16 bits of the ISA address bus. Address settings in our ISA bus serial cards is set by DIP switches (selecting bits 11-4) or jumpers.

CAUTION: Electrostatic Sensitive Device.

Use ESD precautions for safe handling.

B&B Electronics 3PXCC cards are factory configured for COM1 IRQ4, and COM2 IRQ3 (2-port models). If you plan on installing the 3PXCC as standard COM1 and COM2, you may leave the address and IRQ set to the factory defaults.

The 3PXCC cards use a 7-position DIP switch to program the binary I/O address of each port on the card. Figure 1 is a drawing of the printed circuit board that shows the locations of the setup switches and jumpers on the 3PXCC cards.

Figure 1. Silk Screen Plot of 3PXCC PCB

Documentation No.3PXCC1x-2x-3903 29 30 Documentation No.3PXCC1x-2x-3903

B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104	B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104
B&B Electronics Ltd – Westlink Comm. Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445	B&B Electronics Ltd – Westlink Comm. Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445