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© Sealevel Systems, Inc. 3588 Manual | SL9008 9/2022
Hardware Setup
Address Selection
The SIO-104+8.485
occupies 8 consecutive I/O locations. The DIP-switch (SW1) is used to set the
base address for these locations. Be careful when selecting the base address as some selections
conflict with existing PC ports. The following table shows the addressing options available. If
different address options are required, please contact Sealevel Systems Technical Support about
a custom option.
SW1-1
SW1-2
SW1-3
Port 1
Port 2
Port 3
Port 4
Port 5
Port 6
Port 7
Port 8
OFF
OFF
OFF
DISABLED
OFF
OFF
ON
300
308
310
318
320
328
330
338
OFF
ON
OFF
400
408
410
418
420
428
430
438
OFF
ON
ON
500
508
510
518
520
528
530
538
ON
OFF
OFF
600
608
610
618
620
628
630
638
ON
OFF
ON
1500 1508 1510 1518 1520 1528 1530 1538
ON
ON
OFF
3220 3228 3230 3238 3240 3248 3250 3258
ON
ON
ON
4220 4228 4230 4238 4240 4248 4250 4258
Interrupt Configuration
The board is set up to always share interrupts. There is a jumper labeled “PD” which is located at
(E1) on the SIO-104+8.485. Setting this jumper enables a 1K-ohm pull-down (biasing) resistor
required on one adapter when sharing interrupts. The jumper should always be enabled on single
SIO-104+8.485 installations (non-shared mode). In multiple SIO-104+8.485 installations, only one
board should have the jumper enabled.
IRQ Selection
The SIO-104+8.485
has an interrupt selection jumper located at (E1), which should be set prior to
use, if an interrupt is required by your application software. Consult the user manual for the
application software being used to determine the proper setting.
The SIO-104+8.485 supports the following interrupts: 3, 4, 5, 7, 9, 10, 11, 12, and 15.
Clock Modes
The SIO-104+8.485
utilizes a 14.7456 MHz oscillator. This is eight times faster than the standard
COM: port oscillator, which typically is 1.8432 MHz. This allows the adapter to achieve a maximum
data rate of 921.6Kbps. The following sections outline the baud rate calculations and instructions
for achieving your desired baud rate.
