Manual Document# 3PXCC4A3001 31
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
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.
B&B Electronics 3PXCC4A cards are factory configured for
COM1 (IRQ4), COM2 (IRQ3), COM3 (IRQ5), and COM4 (IRQ7). If
you plan on installing two of the four ports on the 3PXCC4A as
standard COM1 and COM2, you may leave the address and IRQ set
to the factory defaults for COM1 and COM2.
The 3PXCC4A 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 3PXCC4A cards.
CAUTION: Electrostatic Sensitive Device.
Use ESD precautions for safe handling.