SeaLevel ACB-188 User manual

ACB-188™
PART # 4019
USER MANUAL
SECTIONS:
1. Installation
2. Address Selection
3. Option Selection
4. Technical Description
5. Product Specifications
6. Warranty
7. Appendix A
FIGURES:
1. Address Selection Table
2. Dip Switch (SW1) Illustration
3. Header E2 -IRQ Selections
4. Header E3 -IRQ Mode Selections
5. Header E1 -RTS Enable Selections
6. Header E4 -MIL-188-114 Selection and Connector Pin-Outs
7. Header E4 -MIL-188-C Selection and Connector Pin-Outs
8. Header E4 -MIL-188-200 Selection and Connector Pin-Outs
Sealevel Systems, Incorporated
155 Technology Place
P.O. Box 830
Liberty, SC 29657 USA
[phone] FAX [phone]
© 1996d Sealevel Systems, Incorporated

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Sealevel Systems ACB-188 Page 1
SECTION 1. Installation
The ACB-188 can be installed in any of the PC expansion slots. Remove the PC case,
remove the blank metal slot cover, and insert the board. Replace the screw, replace the case,
and installation is complete.
Be sure to set the address and jumper options before installation.
SECTION 2. Address Selection
The ACB-188 occupies 8 consecutive I/O locations. A 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 several examples that
usually do not cause a conflict.
Address Binary Switch Settings
Hex A9-----------A0 1234567
238-23F 1000111XXX Off On On On Off Off Off
280-287 1010000XXX Off On Off On On On On
2A0-2A7 1010100XXX Off On Off On Off On On
2E8-2EF 1011101XXX Off On Off Off Off On Off
300-307 1100000XXX Off Off On On On On On
328-32F 1100101XXX Off Off On On Off On Off
3E8-3EF 1111101XXX Off Off Off Off Off On Off
TYPICALLY COM1:=3F8h; COM2:=2F8h; COM3:=3E8h; COM4:=2E8h.
Figure 1
Address Selection Table
The following illustration shows the correlation between the DIP-switch setting and the
address bits used to determine the base address. In the example below, the address 300
Hex through 307 Hex is selected. 300 Hex =11 0000 0XXX in binary representation.
ON
OFF
1 2 3 4 5 6 7
`A9 A3
8
EN
Figure 2
DIP-switch SW-1
Note: Setting the switch "On" or "Closed" corresponds to a "0" in the address, while leaving it
"Off" or "Open" corresponds to a "1".
The ACB-188 can be enabled or disabled with switch position 8 on the DIP-switch. The port
is enabled with the switch "On" or "Closed" and disabled when "Off" or "Open".
The relative I/O address of the 8530 SCC registers is as follows:
•Base+0 Channel A Data Port
•Base+1 Channel A Control Port
•Base+2 Channel B Data Port
•Base+3 Channel B Control Port
Where "Base" is the selected board base address.

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Sealevel Systems ACB-188 Page 2
SECTION 3. Option Selection
The board contains several jumper straps which must be set for proper operation. For jumper
locations, refer to the silk-screen diagram in the back of this manual.
IRQ Selection
E2 -Selects the interrupt request for the ACB-188.
15 12 11 10 7 6 5 4 3 2
Figure 3
Header E2, IRQ 4 Selected
Interrupt Modes
Figure 4.1 illustrates the Normal, single interrupt per port mode. Figure 4.2 illustrates the
Shared interrupt mode, which allows more than one port to access a single IRQ. Figure 4.3
indicates the Multi-port mode that signifies inclusion of a 1K ohm pull-down resistor required
on one port when sharing interrupts.
1
Normal
Figure 4.1:
Header E3 Illustration Part 1.

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Sealevel Systems ACB-188 Page 3
Figure 4.2 illustrates the Shared interrupt mode, which allows more than one port to access a
single IRQ.
Note: Setting the ACB-188 in this configuration when it is not accompanied by a pull-down
resistor (see Figure 4.3) will prevent the ports from triggering an interrupt.
1
Shared
Figure 4.2
Header E3 Illustration Part 2.
If shared interrupts are required on two or more ACB-188’s set the jumpers for shared
interrupt mode on all ports sharing an IRQ except one. Set that port block as the example
4.3. This provides the pull-down resistor circuit that makes sharing of IRQ’s possible. If you
are using more than one ACB-188 or a compatible card in a bus you should only have one
port set as Figure 4.3.
1
Multi
Figure 4.3
Header E3 Illustration Part 3.

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Sealevel Systems ACB-188 Page 4
E1 -On port 1 to have the driver enabled by RTS place the jumper at the “RTS” A position.
To have the driver always enabled or always on place the jumper at the “ON” A position. On
port 2 to have the driver enabled by RTS place the jumper at the “RTS” B position. To have the
driver always enabled or always on place the jumper at the “ON” B position.
E1
1RTS
ON
RTS
ON
A
B
Figure 5.
E4 -A unique feature of the ACB-188 is the capability to receive single ended transmissions
or differential transmissions. Placing the jumpers in the “B” position ground the unused pins
allowing single ended reception. To select differential transmissions place all jumpers in the
“B” position as shown in Figure 6. To select single ended positive (+) transmissions place
jumpers as shown in Figure 7. To select single ended negative (-) transmissions place the
jumpers as shown in Figure 8.
Signal Name DB-15 PIN #
Transmit Positive TX+ 6
Transmit Negative TX-2
Request to Send Positive RTS + 5
Request to Send Negative RTS -4
Receive Data Positive RD+ 8
Receive Data Negative RD-3
Receive Clock Positive RXC + 9
Receive Clock Negative RXC -10
Ground GND 7
“Push to Talk” PTT 15
Figure 6
MIL-188-114 Differential
Signal Name: DB-15 PIN #
Transmit TX 6
Request to Send RTS 5
Receive Data RD 8
Receive Clock RXC 9
Ground GND 7
“Push to Talk” PTT 15
Figure 7
MIL-188-C Single Ended Positive Logic
AB
E4
1
AB
E4
1