Card Setup; Address Selection; Figure 1 - Address Selection Table; Figure 2 - Dip-Switch Illustration - Omega Engineering OMG-COMM2-EX User Manual

Dual port isa rs-232/422/485 interface board
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The OMG-COMM2-EX contains several jumper straps which must be set for
proper operation.

Address Selection

Each port on the OMG-COMM2-EX occupies eight consecutive I/O locations. A
DIP-switch is used to set the base address for these locations. Be careful when
selecting the base address as some selections conflict with existing ports. The
following table shows several examples that typically do not cause a conflict.
SW1 sets the I/O address for port 1 of the OMG-COMM2-EX and SW2 sets the
address for port 2.
Address
Binary
Hex
A9
A0
280-287
1010000XXX
2A0-2A7
1010100XXX
2E8-2EF
1011101XXX
2F8-2FF
1011111XXX
3E8-3EF
1111101XXX
300-307
1100000XXX
328-32F
1100101XXX
3F8-3FF
1111111XXX

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,
address 300 is selected as a base. Address 300 in binary is XX11 0000 0XXX
where X = a non-selectable address bit.

Figure 2 - DIP-Switch Illustration

Note: Setting the switch 'On' or 'Closed' corresponds to a '0' in the address,
while leaving it 'Off' or 'Open' corresponds to a '1'.
Refer to Appendix A for common address contentions.
OMG-COMM2-EX

Card Setup

Switch Position Setting
1
2
3
Off
On
Off
Off
On
Off
Off
On
Off
Off
On
Off
Off
Off
Off
Off
Off
On
Off
Off
On
Off
Off
Off
A9
A3
ON
1
2
3
4
5
6
7
Card Setup
4
5
6
7
On
On
On
On
On
Off
On
On
Off
Off
On
Off
Off
Off
Off
Off
Off
Off
On
Off
On
On
On
On
On
Off
On
Off
Off
Off
Off
Off
EN
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